0032132人目の素数さん2021/02/23(火) 23:29:48.30ID:RLePkY5e 局所は、局所化:環に乗法逆元を機械的に添加する 局所環:In practice, a commutative local ring often arises as the result of the localization of a ring at a prime ideal. The English term local ring is due to Zariski.[2]
https://ja.wikipedia.org/wiki/%E7%92%B0%E3%81%AE%E5%B1%80%E6%89%80%E5%8C%96 環の局所化(きょくしょか、英: localization)あるいは分数環 (ring of fraction)、商環 (ring of quotient)[注 1] は、環に乗法逆元を機械的に添加する方法である。すなわち、環 R とその部分集合 S が与えられたとき、環 R' と R から R' への環準同型を構成して、S の準同型像が R' における単元(可逆元)のみからなるようにする。さらに、R' が「可能な限りで最良な」あるいは「最も一般な」ものとなるようにするということを考える(こういった状況はふつうは普遍性によって表されるべきものである)。環 R の部分集合 S による局所化は S−1R で表され、あるいは S が素イデアル {p} の補集合であるときには R_ {p}} で表される。S−1R のことを RS と表すこともあるが、通常混乱の恐れはない。
局所化は完備化と重要な関係があり、環を局所化すると完備になるということがよくある。
用語について 「局所化」の名の起源は代数幾何学にある。R はある幾何学的対象(代数多様体)の上で定義された函数環とする。この多様体を点 p の近傍で「局所的に」調べようとするならば、p の近傍で 0 でないような函数全体の成す集合 S を考えることになる。その意味で、R を S に関して局所化して得られる環 S−1R は p の近傍における V の挙動についての情報のみをふくんでいる(局所環も参照)。
例 整数環を Z, 有理数体を Q と表す。
R = Z のとき、積閉集合 S = Z − {0} による局所化は S−1R = Q である。
https://en.wikipedia.org/wiki/Local_ring In abstract algebra, more specifically ring theory, local rings are certain rings that are comparatively simple, and serve to describe what is called "local behaviour", in the sense of functions defined on varieties or manifolds, or of algebraic number fields examined at a particular place, or prime. Local algebra is the branch of commutative algebra that studies commutative local rings and their modules.
In practice, a commutative local ring often arises as the result of the localization of a ring at a prime ideal.
The concept of local rings was introduced by Wolfgang Krull in 1938 under the name Stellenringe.[1] The English term local ring is due to Zariski.[2]
Examples All fields (and skew fields) are local rings, since {0} is the only maximal ideal in these rings. A nonzero ring in which every element is either a unit or nilpotent is a local ring. 0033132人目の素数さん2021/02/26(金) 10:41:04.06ID:/iWCqc/x 田口 雄一郎先生、結構面白い
http://www.math.titech.ac.jp/~taguchi/nihongo/abc.html abc予想の話 ( 昔、北大理学部 HP の「サイエンストピックス」に掲載されたもの ) 田口 雄一郎 http://www.math.titech.ac.jp/~taguchi/nihongo/bunsho.html Yuichiro TAGUCHI 0035132人目の素数さん2021/02/27(土) 23:24:57.49ID:f+hU2HEr>>34 メモ https://en.wikipedia.org/wiki/Klein_quartic Klein quartic In hyperbolic geometry, the Klein quartic, named after Felix Klein, is a compact Riemann surface of genus 3 with the highest possible order automorphism group for this genus, namely order 168 orientation-preserving automorphisms, and 336 automorphisms if orientation may be reversed. As such, the Klein quartic is the Hurwitz surface of lowest possible genus; see Hurwitz's automorphisms theorem. Its (orientation-preserving) automorphism group is isomorphic to PSL(2, 7), the second-smallest non-abelian simple group. The quartic was first described in (Klein 1878b).
Closed and open forms It is important to distinguish two different forms of the quartic. The closed quartic is what is generally meant in geometry; topologically it has genus 3 and is a compact space. The open or "punctured" quartic is of interest in number theory; topologically it is a genus 3 surface with 24 punctures, and geometrically these punctures are cusps. The open quartic may be obtained (topologically) from the closed quartic by puncturing at the 24 centers of the tiling by regular heptagons, as discussed below. The open and closed quartics have different metrics, though they are both hyperbolic and complete[1] – geometrically, the cusps are "points at infinity", not holes, hence the open quartic is still complete.
Affine quartic The above is a tiling of the projective quartic (a closed manifold); the affine quartic has 24 cusps (topologically, punctures), which correspond to the 24 vertices of the regular triangular tiling, or equivalently the centers of the 24 heptagons in the heptagonal tiling, and can be realized as follows.
Considering the action of SL(2, R) on the upper half-plane model H2 of the hyperbolic plane by Möbius transformations, the affine Klein quartic can be realized as the quotient Γ(7)\H2. (Here Γ(7) is the congruence subgroup of SL(2, Z) consisting of matrices that are congruent to the identity matrix when all entries are taken modulo 7.)
Dessin d'enfants The dessin d'enfant on the Klein quartic associated with the quotient map by its automorphism group (with quotient the Riemann sphere) is precisely the 1-skeleton of the order-3 heptagonal tiling.[10] That is, the quotient map is ramified over the points 0, 1728, and ∞; dividing by 1728 yields a Belyi function (ramified at 0, 1, and ∞), where the 56 vertices (black points in dessin) lie over 0, the midpoints of the 84 edges (white points in dessin) lie over 1, and the centers of the 24 heptagons lie over infinity. The resulting dessin is a "platonic" dessin, meaning edge-transitive and "clean" (each white point has valence 2).
https://en.wikipedia.org/wiki/Klein_quadric Klein quadric In mathematics, the lines of a 3-dimensional projective space, S, can be viewed as points of a 5-dimensional projective space, T. In that 5-space, the points that represent each line in S lie on a quadric, Q known as the Klein quadric.
If the underlying vector space of S is the 4-dimensional vector space V, then T has as the underlying vector space the 6-dimensional exterior square Λ2V of V. The line coordinates obtained this way are known as Plücker coordinates. 以上 0038132人目の素数さん2021/02/27(土) 23:36:36.38ID:f+hU2HEr>>37
Punctured spheres These statements are clarified by considering the type of a Riemann sphere {\displaystyle {\widehat {\mathbf {C} }}}\widehat{\mathbf{C}} with a number of punctures. With no punctures, it is the Riemann sphere, which is elliptic. With one puncture, which can be placed at infinity, it is the complex plane, which is parabolic. With two punctures, it is the punctured plane or alternatively annulus or cylinder, which is parabolic. With three or more punctures, it is hyperbolic – compare pair of pants. One can map from one puncture to two, via the exponential map (which is entire and has an essential singularity at infinity, so not defined at infinity, and misses zero and infinity), but all maps from zero punctures to one or more, or one or two punctures to three or more are constant.
Isometries of Riemann surfaces The isometry group of a uniformized Riemann surface (equivalently, the conformal automorphism group) reflects its geometry: ・the isometry group of the plane is the subgroup fixing infinity, and of the punctured plane is the subgroup leaving invariant the set containing only infinity and zero: either fixing them both, or interchanging them (1/z). 0039132人目の素数さん2021/02/28(日) 08:21:52.42ID:c9K39yvS>>24 ありがとう (追加) https://en.wikipedia.org/wiki/Dessin_d%27enfant Dessin d'enfant Contents 1 History 1.1 19th century 1.2 20th century 2 Riemann surfaces and Belyi pairs 3 Maps and hypermaps 4 Regular maps and triangle groups 5 Trees and Shabat polynomials 6 The absolute Galois group and its invariants
Riemann surfaces and Belyi pairs Each triangle in the triangulation has three vertices labeled 0 (for the black points), 1 (for the white points), or ∞. For each triangle, substitute a half-plane, either the upper half-plane for a triangle that has 0, 1, and ∞ in counterclockwise order or the lower half-plane for a triangle that has them in clockwise order, and for every adjacent pair of triangles glue the corresponding half-planes together along the portion of their boundaries indicated by the vertex labels. The resulting Riemann surface can be mapped to the Riemann sphere by using the identity map within each half-plane. Thus, the dessin d'enfant formed from f is sufficient to describe f itself up to biholomorphism. However, this construction identifies the Riemann surface only as a manifold with complex structure; it does not construct an embedding of this manifold as an algebraic curve in the complex projective plane, although such an embedding always exists.
The same construction applies more generally when X is any Riemann surface and f is a Belyi function; that is, a holomorphic function f from X to the Riemann sphere having only 0, 1, and ∞ as critical values. A pair (X, f) of this type is known as a Belyi pair. From any Belyi pair (X, f) one can form a dessin d'enfant, drawn on the surface X, that has its black points at the preimages f-1(0) of 0, its white points at the preimages f-1(1) of 1, and its edges placed along the preimages f-1([0, 1]) of the line segment [0, 1]. Conversely, any dessin d'enfant on any surface X can be used to define gluing instructions for a collection of halfspaces that together form a Riemann surface homeomorphic to X; mapping each halfspace by the identity to the Riemann sphere produces a Belyi function f on X, and therefore leads to a Belyi pair (X, f). Any two Belyi pairs (X, f) that lead to combinatorially equivalent dessins d'enfants are biholomorphic, and Belyi's theorem implies that, for any compact Riemann surface X defined over the algebraic numbers, there are a Belyi function f and a dessin d'enfant that provides a combinatorial description of both X and f.
Maps and hypermaps A vertex in a dessin has a graph-theoretic degree, the number of incident edges, that equals its degree as a critical point of the Belyi function.
Thus, any embedding of a graph in a surface in which each face is a disk (that is, a topological map) gives rise to a dessin by treating the graph vertices as black points of a dessin, and placing white points at the midpoint of each embedded graph edge. If a map corresponds to a Belyi function f, its dual map (the dessin formed from the preimages of the line segment [1, ∞]) corresponds to the multiplicative inverse 1/f.[5]
A dessin that is not clean can be transformed into a clean dessin in the same surface, by recoloring all of its points as black and adding new white points on each of its edges. The corresponding transformation of Belyi pairs is to replace a Belyi function β by the pure Belyi function γ = 4β(1 - β).
The absolute Galois group and its invariants The two choices of a lead to two Belyi functions f1 and f2. These functions, though closely related to each other, are not equivalent, as they are described by the two nonisomorphic trees shown in the figure.
However, as these polynomials are defined over the algebraic number field Q(√21), they may be transformed by the action of the absolute Galois group Γ of the rational numbers. An element of Γ that transforms √21 to -√21 will transform f1 into f2 and vice versa, and thus can also be said to transform each of the two trees shown in the figure into the other tree.
More generally, due to the fact that the critical values of any Belyi function are the pure rationals 0, 1, and ∞, these critical values are unchanged by the Galois action, so this action takes Belyi pairs to other Belyi pairs. One may define an action of Γ on any dessin d'enfant by the corresponding action on Belyi pairs; this action, for instance, permutes the two trees shown in the figure.
Due to Belyi's theorem, the action of Γ on dessins is faithful (that is, every two elements of Γ define different permutations on the set of dessins),[10] so the study of dessins d'enfants can tell us much about Γ itself.
The two Belyi functions f1 and f2 of this example are defined over the field of moduli, but there exist dessins for which the field of definition of the Belyi function must be larger than the field of moduli.[11] (引用終り) 以上 0042132人目の素数さん2021/02/28(日) 16:01:49.39ID:c9K39yvS メモ https://en.wikipedia.org/wiki/Algebraic_stack Algebraic stack
In mathematics, an algebraic stack is a vast generalization of algebraic spaces, or schemes, which are foundational for studying moduli theory. Many moduli spaces are constructed using techniques specific to algebraic stacks, such as Artin's representability theorem, which is used to construct the moduli space of pointed algebraic curves {\displaystyle {\mathcal {M}}_{g,n}}{\mathcal {M}}_{{g,n}} and the moduli stack of elliptic curves. Originally, they were introduced by Grothendieck[1] to keep track of automorphisms on moduli spaces, a technique which allows for treating these moduli spaces as if their underlying schemes or algebraic spaces are smooth. But, through many generalizations the notion of algebraic stacks was finally discovered by Michael Artin.[2]
http://www.math.chuo-u.ac.jp/morita_newser.htm 森田茂之氏による特別講演:新シリーズ(ENCOUNTERwithMATHEMATICS番外編)中央大学 2013年秋から、全体を仕切りなおして新シリーズを開始します. http://www.math.chuo-u.ac.jp/LN_in_Chuo_v11.pdf トポロジーの課題探訪 ―特性類と不変量を中心として― 森田茂之 2013 年 10 月 9 日- 0046132人目の素数さん2021/03/21(日) 06:55:19.90ID:00ruIs7L メモ https://en.wikipedia.org/wiki/Perverse_sheaf Perverse sheaf The mathematical term perverse sheaves refers to a certain abelian category associated to a topological space X, which may be a real or complex manifold, or a more general topologically stratified space, usually singular. This concept was introduced in the thesis of Zoghman Mebkhout, gaining more popularity after the (independent) work of Joseph Bernstein, Alexander Beilinson, and Pierre Deligne (1982) as a formalisation of the Riemann-Hilbert correspondence, which related the topology of singular spaces (intersection homology of Mark Goresky and Robert MacPherson) and the algebraic theory of differential equations (microlocal calculus and holonomic D-modules of Joseph Bernstein, Masaki Kashiwara and Takahiro Kawai). It was clear from the outset that perverse sheaves are fundamental mathematical objects at the crossroads of algebraic geometry, topology, analysis and differential equations. They also play an important role in number theory, algebra, and representation theory. The properties characterizing perverse sheaves already appeared in the 75's paper of Kashiwara on the constructibility of solutions of holonomic D-modules.
Contents 1 Preliminary remarks 2 Definition and examples 3 Properties 4 Applications 5 String Theory
String Theory Massless fields in superstring compactifications have been identified with cohomology classes on the target space (i.e. four-dimensional Minkowski space with a six-dimensional Calabi-Yau (CY) manifold). The determination of the matter and interaction content requires a detailed analysis of the (co)homology of these spaces: nearly all massless fields in the effective physics model are represented by certain (co)homology elements. However, a troubling consequence occurs when the target space is singular. A singular target space means that only the CY manifold is singular as Minkowski space is smooth. Such a singular CY manifold is called a conifold as it is a CY manifold that admits conical singularities. Andrew Strominger observed (A. Strominger, 1995) that conifolds correspond to massless blackholes.
These singular target spaces, i.e. conifolds, correspond to certain mild degenerations of algebraic varieties which appear in a large class of supersymmetric theories, including superstring theory (E. Witten, 1982).
In the winter of 2002, T. Hubsch and A. Rahman met with R.M. Goresky to discuss this obstruction and in discussions between R.M. Goresky and R. MacPherson, R. MacPherson made the observation that there was such a perverse sheaf that could have the cohomology that satisfied Hubsch's conjecture and resolved the obstruction. R.M. Goresky and T. Hubsch advised A. Rahman's Ph.D. dissertation on the construction of a self-dual perverse sheaf (A. Rahman, 2009) using the zig-zag construction of MacPherson-Vilonen (R. MacPherson & K. Vilonen, 1986). This perverse sheaf proved the Hübsch conjecture for isolated conic singularities, satisfied Poincarè duality, and aligned with some of the properties of the Kähler package.
Satisfaction of all of the Kähler package by this Perverse sheaf for higher codimension strata is still an open problem.
https://arxiv.org/pdf/1806.06129.pdf CATEGORICAL NOTIONS OF FIBRATION FOSCO LOREGIAN AND EMILY RIEHL Date: Original version December 20, 2010; revised version February 19, 2019.
https://en.wikipedia.org/wiki/Fibred_category Fibred categories (or fibered categories) are abstract entities in mathematics used to provide a general framework for descent theory. Similar setups appear in various guises in mathematics, in particular in algebraic geometry, which is the context in which fibred categories originally appeared. Fibered categories are used to define stacks, which are fibered categories (over a site) with "descent". Fibrations also play an important role in categorical semantics of type theory, and in particular that of dependent type theories. Fibred categories were introduced by Alexander Grothendieck (1959, 1971), and developed in more detail by Jean Giraud (1964, 1971). 0050132人目の素数さん2021/03/26(金) 07:30:20.63ID:tYykNeNT>>49 >Fibred categories (or fibered categories) are abstract entities in mathematics used to provide a general framework for descent theory.
追加 https://en.wikipedia.org/wiki/Descent_(mathematics) Descent (mathematics) In mathematics, the idea of descent extends the intuitive idea of 'gluing' in topology. Since the topologists' glue is the use of equivalence relations on topological spaces, the theory starts with some ideas on identification.
Contents 1 Descent of vector bundles 2 History 3 Fully faithful descent
Descent of vector bundles
Therefore, by going to a more abstract level one can eliminate the combinatorial side (that is, leave out the indices) and get something that makes sense for p not of the special form of covering with which we began. This then allows a category theory approach: what remains to do is to re-express the gluing conditions.
History The ideas were developed in the period 1955–1965 (which was roughly the time at which the requirements of algebraic topology were met but those of algebraic geometry were not). From the point of view of abstract category theory the work of comonads of Beck was a summation of those ideas; see Beck's monadicity theorem.
The difficulties of algebraic geometry with passage to the quotient are acute. The urgency (to put it that way) of the problem for the geometers accounts for the title of the 1959 Grothendieck seminar TDTE on theorems of descent and techniques of existence (see FGA) connecting the descent question with the representable functor question in algebraic geometry in general, and the moduli problem in particular. 0051132人目の素数さん2021/03/29(月) 23:34:59.52ID:jhylP48U 「ライプニッツは間違っていたのか?」 「ラインハートは間違っていたのか?」
米田埋め込みとは,任意の局所小圏 C を C 上の前層 presheaf(Cop から Set への関手圏)に埋め込む関 手である.本稿では関手のいくつかの性質の定義を導入し,米田埋め込みを定義する.そしてそれが実際に埋 め込みになっていることを確認する.米田埋め込みとは直接関係はないが,第 1 節では圏同値の二つの定義を 紹介し,それらの定義が等しいことを確認する.
Antitone Galois connections Galois theory The motivating example comes from Galois theory: suppose L/K is a field extension. Let A be the set of all subfields of L that contain K, ordered by inclusion ⊆. If E is such a subfield, write Gal(L/E) for the group of field automorphisms of L that hold E fixed. Let B be the set of subgroups of Gal(L/K), ordered by inclusion ⊆. For such a subgroup G, define Fix(G) to be the field consisting of all elements of L that are held fixed by all elements of G. Then the maps E → Gal(L/E) and G → Fix(G) form an antitone Galois connection.
7 Connection to category theory 8 Applications in the theory of programming
Contents 1 In the school of Grothendieck 2 From pure category theory to categorical logic 3 Position of topos theory 4 Summary
In the school of Grothendieck During the latter part of the 1950s, the foundations of algebraic geometry were being rewritten; and it is here that the origins of the topos concept are to be found. At that time the Weil conjectures were an outstanding motivation to research. As we now know, the route towards their proof, and other advances, lay in the construction of etale cohomology.
Summary The topos concept arose in algebraic geometry, as a consequence of combining the concept of sheaf and closure under categorical operations. It plays a certain definite role in cohomology theories. A 'killer application' is etale cohomology.
The subsequent developments associated with logic are more interdisciplinary. They include examples drawing on homotopy theory (classifying toposes). They involve links between category theory and mathematical logic, and also (as a high-level, organisational discussion) between category theory and theoretical computer science based on type theory. Granted the general view of Saunders Mac Lane about ubiquity of concepts, this gives them a definite status. The use of toposes as unifying bridges in mathematics has been pioneered by Olivia Caramello in her 2017 book.[1]
References Caramello, Olivia (2017). Theories, Sites, Toposes: Relating and studying mathematical theories through topos-theoretic `bridges. Oxford University Press. doi:10.1093/oso/9780198758914.001.0001. ISBN 9780198758914. 0058132人目の素数さん2021/04/10(土) 09:11:58.29ID:BBK6b/st Category Theory Brief Historical Sketch
1. General Definitions, Examples and Applications 1.1 Definitions 1.2 Examples 1.3 Fundamental Concepts of the Theory 2. Brief Historical Sketch 3. Philosophical Significance Bibliography Academic Tools Other Internet Resources Related Entries
2. Brief Historical Sketch It is difficult to do justice to the short but intricate history of the field. In particular it is not possible to mention all those who have contributed to its rapid development. With this word of caution out of the way, we will look at some of the main historical threads.
Categories, functors, natural transformations, limits and colimits appeared almost out of nowhere in a paper by Eilenberg & Mac?Lane (1945) entitled “General Theory of Natural Equivalences.” We say “almost,” because their earlier paper (1942) contains specific functors and natural transformations at work, limited to groups. A desire to clarify and abstract their 1942 results led Eilenberg & Mac?Lane to devise category theory. The central notion at the time, as their title indicates, was that of natural transformation. In order to give a general definition of the latter, they defined functor, borrowing the term from Carnap, and in order to define functor, they borrowed the word ‘category’ from the philosophy of Aristotle, Kant, and C. S. Peirce, but redefining it mathematically. 0059132人目の素数さん2021/04/10(土) 11:36:08.97ID:BBK6b/st メモ 下記 誘(いざな)い 《拡大版》 なかなか良いね http://www.kurims.kyoto-u.ac.jp/~motizuki/travel-japanese.html 望月 出張講演 http://www.kurims.kyoto-u.ac.jp/~motizuki/Uchuusai%20Taihimyuuraa%20riron%20he%20no%20izanai%20(kakudaiban).pdf 望月 出張講演 [13] 宇宙際タイヒミューラー理論への誘(いざな)い 《拡大版》 (東京大学 2013年06月) PDF
過去の論文のレベルでいうと、絶対遠アーベル幾何やエタール・テータ関数の様々な剛性性質に関する ・ Semi-graphs of Anabelioids ・ The Etale Theta Function ... ・ The Geometry of Frobenioids I, II ・ Topics in Absolute Anab. Geo. III の結果や理論を適用することによって主定理を帰結する: 主定理: θ-link の 左辺 に対して、軽微な不定性を除いて、右辺 の「異質」な環構造 しか用いない言葉により、明示的なアルゴリズム による記述を与えることができる。
In combinatorial mathematics, LCF notation or LCF code is a notation devised by Joshua Lederberg, and extended by H. S. M. Coxeter and Robert Frucht, for the representation of cubic graphs that contain a Hamiltonian cycle.[2][3] The cycle itself includes two out of the three adjacencies for each vertex, and the LCF notation specifies how far along the cycle each vertex's third neighbor is. A single graph may have multiple different representations in LCF notation.
LCF notation is a concise and convenient notation devised by Joshua Lederberg (winner of the 1958 Nobel Prize in Physiology and Medicine) for the representation of cubic Hamiltonian graphs (Lederberg 1965). The notation was subsequently modified by Frucht (1976) and Coxeter et al. (1981), and hence was dubbed "LCF notation" by Frucht (1976). Pegg (2003) used the notation to describe many of the cubic symmetric graphs. The notation only applies to Hamiltonian graphs, since it achieves its symmetry and conciseness by placing a Hamiltonian cycle in a circular embedding and then connecting specified pairs of nodes with edges.
Contents 1 Timeline to 1945: before the definitions 2 1945?1970 3 1971?1980 4 1981?1990 5 1991?2000 6 2001?present 7 See also 0066132人目の素数さん2021/04/10(土) 23:22:16.42ID:BBK6b/st メモ Categorical logic - higher-order logics https://en.wikipedia.org/wiki/Categorical_logic Categorical logic
Internal languages This can be seen as a formalization and generalization of proof by diagram chasing. One defines a suitable internal language naming relevant constituents of a category, and then applies categorical semantics to turn assertions in a logic over the internal language into corresponding categorical statements. This has been most successful in the theory of toposes, where the internal language of a topos together with the semantics of intuitionistic higher-order logic in a topos enables one to reason about the objects and morphisms of a topos "as if they were sets and functions".
Further reading Lambek, J. and Scott, P. J., 1986. Introduction to Higher Order Categorical Logic. Fairly accessible introduction, but somewhat dated. The categorical approach to higher-order logics over polymorphic and dependent types was developed largely after this book was published. Jacobs, Bart (1999). Categorical Logic and Type Theory. Studies in Logic and the Foundations of Mathematics 141. North Holland, Elsevier. ISBN 0-444-50170-3. A comprehensive monograph written by a computer scientist; it covers both first-order and higher-order logics, and also polymorphic and dependent types. The focus is on fibred category as universal tool in categorical logic, which is necessary in dealing with polymorphic and dependent types. 0067132人目の素数さん2021/04/11(日) 00:00:34.67ID:DhE75b2I メモ ”He and others went on to show that higher order logic was beautifully captured in the setting of category theory (more specifically toposes).” https://math.mit.edu/~dspivak/ David Spivak Research Scientist Department of Mathematics MIT https://ocw.mit.edu/courses/mathematics/18-s996-category-theory-for-scientists-spring-2013/# Category Theory for Scientists MIT OpenCourseWare, Massachusetts Institute of Technology https://ocw.mit.edu/courses/mathematics/18-s996-category-theory-for-scientists-spring-2013/textbook/ Category Theory for Scientists Textbook https://math.mit.edu/~dspivak/CT4S.pdf Category Theory for Scientists (Old Version) David I. Spivak September 17, 2013
P10 Bill Lawvere saw category theory as a new foundation for all mathematical thought. Mathematicians had been searching for foundations in the 19th century and were reasonably satisfied with set theory as the foundation. But Lawvere showed that the category of sets is simply a category with certain nice properties, not necessarily the center of the mathematical universe. He explained how whole algebraic theories can be viewed as examples of a single system. He and others went on to show that higher order logic was beautifully captured in the setting of category theory (more specifically toposes). It is here also that Grothendieck and his school worked out major results in algebraic geometry. 0068132人目の素数さん2021/04/11(日) 12:37:55.08ID:DhE75b2I メモ(これ、結構いいかも)
In mathematics, categorification is the process of replacing set-theoretic theorems with category-theoretic analogues. Categorification, when done successfully, replaces sets with categories, functions with functors, and equations with natural isomorphisms of functors satisfying additional properties. The term was coined by Louis Crane.
The reverse of categorification is the process of decategorification. Decategorification is a systematic process by which isomorphic objects in a category are identified as equal. Whereas decategorification is a straightforward process, categorification is usually much less straightforward. In the representation theory of Lie algebras, modules over specific algebras are the principle objects of study, and there are several frameworks for what a categorification of such a module should be, e.g., so called (weak) abelian categorifications.[1]
Categorification and decategorification are not precise mathematical procedures, but rather a class of possible analogues. They are used in a similar way to the words like 'generalization', and not like 'sheafification'.[2]
Contents 1 Examples of categorification 2 Abelian categorifications 3 See also
Examples of categorification One form of categorification takes a structure described in terms of sets, and interprets the sets as isomorphism classes of objects in a category. For example, the set of natural numbers can be seen as the set of cardinalities of finite sets (and any two sets with the same cardinality are isomorphic). In this case, operations on the set of natural numbers, such as addition and multiplication, can be seen as carrying information about products and coproducts of the category of finite sets. Less abstractly, the idea here is that manipulating sets of actual objects, and taking coproducts (combining two sets in a union) or products (building arrays of things to keep track of large numbers of them) came first. Later, the concrete structure of sets was abstracted away - taken "only up to isomorphism", to produce the abstract theory of arithmetic. This is a "decategorification" - categorification reverses this step.
Other examples include homology theories in topology. Emmy Noether gave the modern formulation of homology as the rank of certain free abelian groups by categorifying the notion of a Betti number.[3] See also Khovanov homology as a knot invariant in knot theory.
An example in finite group theory is that the ring of symmetric functions is categorified by the category of representations of the symmetric group. The decategorification map sends the Specht module indexed by partition {\displaystyle \lambda }\lambda to the Schur function indexed by the same partition, (引用終り) 以上 0075132人目の素数さん2021/04/12(月) 07:25:20.81ID:e7FQ3ldh メモ https://en.wikipedia.org/wiki/Gluing_axiom Gluing axiom
In mathematics, the gluing axiom is introduced to define what a sheaf {F} on a topological space X must satisfy, given that it is a presheaf, which is by definition a contravariant functor {F}: {O}(X)→ C to a category C}C which initially one takes to be the category of sets. Here {O}(X) is the partial order of open sets of X ordered by inclusion maps; and considered as a category in the standard way, with a unique morphism U→ V if U is a subset of V}V, and none otherwise.
As phrased in the sheaf article, there is a certain axiom that F must satisfy, for any open cover of an open set of X. For example, given open sets U and V with union X and intersection W, the required condition is that {F}(X) is the subset of {F}(U) x {F}(V) With equal image in {F}(W) In less formal language, a section s}s of F}F over X}X is equally well given by a pair of sections :(s',s'') on U and V respectively, which 'agree' in the sense that s' and s''have a common image in {F}(W) under the respective restriction maps {F}(U)→ {F}(W) and {F}(V)→ {F}. The first major hurdle in sheaf theory is to see that this gluing or patching axiom is a correct abstraction from the usual idea in geometric situations. For example, a vector field is a section of a tangent bundle on a smooth manifold; this says that a vector field on the union of two open sets is (no more and no less than) vector fields on the two sets that agree where they overlap.
Given this basic understanding, there are further issues in the theory, and some will be addressed here. A different direction is that of the Grothendieck topology, and yet another is the logical status of 'local existence' (see Kripke?Joyal semantics).
Sheafification To turn a given presheaf {P} into a sheaf {F}, there is a standard device called sheafification or sheaving. The rough intuition of what one should do, at least for a presheaf of sets, is to introduce an equivalence relation, which makes equivalent data given by different covers on the overlaps by refining the covers. One approach is therefore to go to the stalks and recover the sheaf space of the best possible sheaf {F} produced from {P}.
This use of language strongly suggests that we are dealing here with adjoint functors. Therefore, it makes sense to observe that the sheaves on X form a full subcategory of the presheaves on X. Implicit in that is the statement that a morphism of sheaves is nothing more than a natural transformation of the sheaves, considered as functors. Therefore, we get an abstract characterisation of sheafification as left adjoint to the inclusion. In some applications, naturally, one does need a description.
In more abstract language, the sheaves on X}X form a reflective subcategory of the presheaves (Mac Lane?Moerdijk Sheaves in Geometry and Logic p. 86). In topos theory, for a Lawvere?Tierney topology and its sheaves, there is an analogous result (ibid. p. 227). (引用終り) 以上 0077132人目の素数さん2021/04/12(月) 07:33:45.32ID:e7FQ3ldh>>74 >Other examples include homology theories in topology. Emmy Noether gave the modern formulation of homology as the rank of certain free abelian groups by categorifying the notion of a Betti number.[3] See also Khovanov homology as a knot invariant in knot theory.
概要 結び目もしくは絡み目 L を表現する図形 D に、コバノフ括弧 [D]、これは次数付きベクトル空間の鎖複体、を割り当てる。すると、ジョーンズ多項式の構成の中でのカウフマン括弧の類似物となる。次に、[D] を(次数付きベクトル空間の中の)一連の次数シフトと(鎖複体の中の)高さシフトにより正規化して、新しい複体 C(D) を得る。この複体のホモロジーは L の不変量であることが分かり、その次数付きオイラー標数は L のジョーンズ多項式であることが分かる。
Contents 1 Overview 2 Definition 3 Related theories 4 The relation to link (knot) polynomials 5 Applications 0078132人目の素数さん2021/04/12(月) 07:40:30.82ID:e7FQ3ldh>>75 追加
anser 45 One way to think of categorification is that it's a generalization of enumerative combinatorics. When a combinatorialist sees a complicated formula that turns out to be positive they think "aha! this must be counting the size of some set!" and when they see an equality of two different positive formulas they think "aha! there must be a bijection explaining this equality!" This is a special case of categorification, because when you decategorify a set you just get a number and when you decategorify a bijection you just get an equality. As a combinatorialist I'm sure you can come up with some examples that nicely illustrate how this sort of categorification is not totally well-defined. ("What exactly do Catalan numbers count?" has many answers rather than a single right answer.)
A more sophisticated kind of categorification in combinatorics is "Combinatorial Species" which categorify power series with positive coefficients. 0079132人目の素数さん2021/04/12(月) 07:42:49.45ID:e7FQ3ldh>>78 追加
Contents 1. Idea 2. Variants As a section of decategorification Examples As internalization in nCat Examples As homotopy coherent resolution Examples 3. Contrast to horizontal categorification 4. Homotopification versus laxification 5. Related entries 6. References
1. Idea
Roughly speaking, vertical categorification is a procedure in which structures are generalized from the context of set theory to category theory or from category theory to higher category theory.
What precisely that means may depend on circumstances and authors, to some extent. The following lists some common procedures that are known as categorification. They are in general different but may in cases lead to the same categorified notions, as discussed in the examples.
See also categorification in representation theory. 0080132人目の素数さん2021/04/12(月) 11:28:58.79ID:Dd3Vb2B3>>78 >One way to think of categorification is that it's a generalization of enumerative combinatorics. When a combinatorialist sees a complicated formula that turns out to be positive they think "aha! this must be counting the size of some set!" and when they see an equality of two different positive formulas they think "aha! there must be a bijection explaining this equality!" >A more sophisticated kind of categorification in combinatorics is "Combinatorial Species" which categorify power series with positive coefficients.
John Carlos Baez / Azimuthは、ちょっと大物かも David Roberts は、三流だと思うが
https://johncarlosbaez.wordpress.com/about/ About Hello! This is the official blog of the Azimuth Project. You can read about many things here: from math to physics to earth science and biology, computer science and the technologies of today and tomorrow—but in general, centered around the theme of what scientists, engineers and programmers can do to help save a planet in crisis.
https://johncarlosbaez.wordpress.com/2018/10/13/category-theory-course/ Azimuth Category Theory Course I’m teaching a course on category theory at U.C. Riverside, and since my website is still suffering from reduced functionality I’ll put the course notes here for now. I taught an introductory course on category theory in 2016, but this one is a bit more advanced.
David Roberts says: 14 October, 2018 at 10:09 pm Amusingly, that example on the first page on lecture one about fd vector spaces having skeleton the standard R^ns is one that Mochizuki (and Go Yamashita, acting as a proxy) claim shouldn’t do! See eg the bottom of page 2 in this FAQ by Yamashita http://www.kurims.kyoto-u.ac.jp/~motizuki/FAQ%20on%20IUTeich.pdf namely the dialogue in A4. Odd…
Reply Todd Trimble says: 15 October, 2018 at 12:00 am I’m somewhat sympathetic to the sentiment that working with a skeleton can be occasionally confusing. Mainly because it can cause one to “see” things which are not actually there! One of my favorite examples is the conceptual distinction between linear orderings of the set \{1, 2, \ldots, n\} and permutations thereon. Because it’s hard not to notice the usual ordering there, it’s very tempting to conflate the two — an urge which goes away when one works not with this skeleton of finite sets, but finite sets more generally, where the distinction becomes totally clear. I gather that Mochizuki (or Yamashita) is driving at something similar.
Reply David Roberts says: 15 October, 2018 at 11:04 am I agree that blind reduction to the skeleton is not the way to do things, but I have taught first-year linear algebra a number of times, and our course uses exclusively the skeleton :-). Not to mention in physics, where everything is R^3 or R^4, and one just makes sure the not-standard basis is explicit.
Blogs Baez runs the blog "Azimuth", where he writes about a variety of topics ranging from This Week's Finds in Mathematical Physics to the current focus, combating climate change and various other environmental issues.[11] (引用終り) 以上 0087132人目の素数さん2021/04/12(月) 17:45:16.37ID:Dd3Vb2B3>>85 >ほいよ >お前下記でも読んでみなw
あんた 読めないんだろ?w(^^ だったら、同じじゃんか!!ww(^^; 0088132人目の素数さん2021/04/12(月) 17:53:22.02ID:Dd3Vb2B3>>85 >http://www.kurims.kyoto-u.ac.jp/~motizuki/FAQ%20on%20IUTeich.pdf namely the dialogue in A4. Odd… (追加) https://www.kurims.kyoto-u.ac.jp/~motizuki/FAQ%20on%20IUTeich.pdf (上記URLと下記URLは同じ内容だが、下記の方が文字化けがないのでいいね) https://www.kurims.kyoto-u.ac.jp/~gokun/DOCUMENTS/IUfaq_en2.pdf FAQ on Inter-universal Teichmüller Theory By Go Yamashita, RIMS, Kyoto University. September 2018
Q8. Can you give examples of further research or results that arose from inter-universal Teichmüller theory? A8. I myself am interested in pursuing the possibility of applying various ideas that appear in inter-universal Teichmüller theory to the study of the Riemann zeta function. At the present
time, I have obtained some interesting observations, but no substantive results. Hoshi is studying an application of inter-universal Teichmüller theory to the birational section conjecture in birational anabelian geometry, while Porowski and Minamide are studying numerical improvements of certain height inequalities in inter-universal Teichmüller theory. I also hear that Dimitrov is studying the possibility of applying inter-universal Teichmüller theory to the study of Siegel-zeroes. References [pGC] S. Mochizuki, The Local Pro-p Anabelian Geometry of Curves. Invent. Math. 138 (1999), p.319423. [EtTh] S. Mochizuki, The Étale Theta Function and its Frobenioid-theoretic Manifestations. Publ. Res. Inst. Math. Sci. 45 (2009), p.227349. [AbsTopII] S. Mochizuki, Topics in Absolute Anabelian Geometry II: Decomposition Groups. J. Math. Sci. Univ. Tokyo 20 (2013), p.171269. [AbsTopIII] S. Mochizuki, Topics in Absolute Anabelian Geometry III: Global Reconstruction Algorithms. J. Math. Sci. Univ. Tokyo 22 (2015), p.9391156. [FAQ] G. Yamashita, FAQ on Inter-Universality, an informal note available at http://www.kurims.kyoto-u.ac.jp/~motizuki/research-english.html [Y] G. Yamashita, A proof of the abc conjecture after Mochizuki, preprint available at http://www.kurims.kyoto-u.ac.jp/~gokun/myworks.html 0089132人目の素数さん2021/04/14(水) 21:50:00.36ID:xXqRObsR>>80
1995 John Baez-James Dolan Opetopic sets (opetopes) based on operads. Weak n-categories are n-opetopic sets. 1995 John Baez-James Dolan Introduced the periodic table of mathematics which identifies k-tuply monoidal n-categories. It mirrors the table of homotopy groups of the spheres. 1995 John Baez?James Dolan Outlined a program in which n-dimensional TQFTs are described as n-category representations. 1995 John Baez?James Dolan Proposed n-dimensional deformation quantization. 1995 John Baez?James Dolan Tangle hypothesis: The n-category of framed n-tangles in n + k dimensions is (n + k)-equivalent to the free weak k-tuply monoidal n-category with duals on one object.
1995 John Baez-James Dolan Cobordism hypothesis (Extended TQFT hypothesis I): The n-category of which n-dimensional extended TQFTs are representations, nCob, is the free stable weak n-category with duals on one object. 1995 John Baez-James Dolan Stabilization hypothesis: After suspending a weak n-category n + 2 times, further suspensions have no essential effect. The suspension functor S: nCatk→nCatk+1 is an equivalence of categories for k = n + 2. 1995 John Baez-James Dolan Extended TQFT hypothesis II: An n-dimensional unitary extended TQFT is a weak n-functor, preserving all levels of duality, from the free stable weak n-category with duals on one object to nHilb.
https://en.wikipedia.org/wiki/John_C._Baez John Carlos Baez (/?ba??z/; born June 12, 1961) is an American mathematical physicist and a professor of mathematics at the University of California, Riverside (UCR)[2] in Riverside, California. He has worked on spin foams in loop quantum gravity, applications of higher categories to physics, and applied category theory.
Baez is also the author of This Week's Finds in Mathematical Physics,[3] an irregular column on the internet featuring mathematical exposition and criticism. (引用終り) 以上 0092132人目の素数さん2021/04/14(水) 23:28:54.47ID:xXqRObsR>>89 圏論化
自明に自明 一つ目は、通常の数学について、 どこが特殊性を使っているところで、 どこが一般論から従うところかを切り分ける手段を提供するところでしょう。 スローガンで言えば、Jon Peter Mayによる
Perhaps the purpose of categorical algebra is to show that which is formal is formally formal. や、その元となったPeter John Freydによる
Perhaps the purpose of categorical algebra is to show that which is trivial is trivially trivial. になるかと思います(これらの出典や意味については、Mathematics Stack Exchangeの「“The purpose of being categorical is to make that which is formal, formally formal” what does it mean?」が参考になります)。
Pavel Samuilovich Urysohn (February 3, 1898 ? August 17, 1924) was a Soviet mathematician who is best known for his contributions in dimension theory, and for developing Urysohn's metrization theorem and Urysohn's lemma, both of which are fundamental results in topology. His name is also commemorated in the terms Urysohn universal space, Frechet?Urysohn space, Menger?Urysohn dimension and Urysohn integral equation. He and Pavel Alexandrov formulated the modern definition of compactness in 1923. 0100132人目の素数さん2021/04/17(土) 11:59:07.65ID:cr30r3uy メモ https://ja.wikipedia.org/wiki/%E3%83%95%E3%83%AD%E3%83%99%E3%83%8B%E3%82%AA%E3%82%A4%E3%83%89 数論幾何学では、フロベニオイドは、グローバルフィールドの有限拡張のモデルでの線束の理論を一般化する追加の構造を持つ圏である。フロベニオイドは望月新一(2008)によって導入された。「フロベニオイド」という言葉は、フロベニウスとモノイドを合わせたものである。フロベニオイド間の特定のフロベニウス射は、通常のフロベニウス射の類似物であり、フロベニオイドの最も単純な例のいくつかは、本質的にモノイドである。
参考文献 望月, 新一 (2008), “The geometry of Frobenioids. I. The general theory”, Kyushu Journal of Mathematics 62 (2): 293?400, doi:10.2206/kyushujm.62.293, ISSN 1340-6116, MR2464528 望月, 新一 (2008), “The geometry of Frobenioids. II. Poly-Frobenioids”, Kyushu Journal of Mathematics 62 (2): 401?460, doi:10.2206/kyushujm.62.401, ISSN 1340-6116, MR2464529 望月, 新一 (2009), “The etale theta function and its Frobenioid-theoretic manifestations”, Kyoto University. Research Institute for Mathematical Sciences. Publications 45 (1): 227?349, doi:10.2977/prims/1234361159, ISSN 0034-5318, MR2512782 Mochizuki, Shinichi (2011), Comments
外部リンク エタール・テータ関数とは何ですか? https://mathoverflow.net/questions/195841/what-is-an-%c3%a9tale-theta-function What is an etale theta function? asked Feb 6 '15 at 14:06 Minhyong Kim (引用終り) 以上 0102132人目の素数さん2021/04/17(土) 12:52:51.59ID:cr30r3uy メモ https://www.kurims.kyoto-u.ac.jp/~motizuki/Topics%20in%20Absolute%20Anabelian%20Geometry%20III.pdf TOPICS IN ABSOLUTE ANABELIAN GEOMETRY III: GLOBAL RECONSTRUCTION ALGORITHMS Shinichi Mochizuki November 2015
Abstract. In the present paper, which forms the third part of a three-part series on an algorithmic approach to absolute anabelian geometry, we apply the absolute anabelian technique of Belyi cuspidalization developed in the second part, together with certain ideas contained in an earlier paper of the author concerning the category-theoretic representation of holomorphic structures via either the topological group SL2(R) or the use of “parallelograms, rectangles, and squares”, to develop a certain global formalism for certain hyperbolic orbicurves related to a oncepunctured elliptic curve over a number field. This formalism allows one to construct certain canonical rigid integral structures, which we refer to as log-shells, that are obtained by applying the logarithm at various primes of a number field. Moreover, although each of these local logarithms is “far from being an isomorphism” both in the sense that it fails to respect the ring structures involved and in the sense [cf. Frobenius morphisms in positive characteristic!] that it has the effect of exhibiting the “mass” represented by its domain as a “somewhat smaller collection of mass” than the “mass” represented by its codomain, this global formalism allows one to treat the logarithm operation as a global operation on a number field which satisfies the property of being an “isomomorphism up to an appropriate renormalization operation”, in a fashion that is reminiscent of the isomorphism induced on differentials by a Frobenius lifting, once one divides by p.
More generally, if one thinks of number fields as corresponding to positive characteristic hyperbolic curves and of once-punctured elliptic curves on a number field as corresponding to nilpotent ordinary indigenous bundles on a positive characteristic hyperbolic curve, then many aspects of the theory developed in the present paper are reminiscent of [the positive characteristic portion of] p-adic Teichm¨uller theory.
Introduction §I1. Summary of Main Results §I2. Fundamental Naive Questions Concerning Anabelian Geometry §I3. Dismantling the Two Combinatorial Dimensions of a Ring §I4. Mono-anabelian Log-Frobenius Compatibility §I5. Analogy with p-adic Teichm¨uller Theory Acknowledgements (引用終り) 以上 0104132人目の素数さん2021/04/17(土) 15:05:33.76ID:8MN6ablF IUTは数学というかグロタン宇宙論になってるな 0105132人目の素数さん2021/04/17(土) 17:29:17.92ID:cr30r3uy>>104 >IUTは数学というかグロタン宇宙論になってるな
2021年04月15日 ・(論文)修正版を更新 https://www.kurims.kyoto-u.ac.jp/~motizuki/Essential%20Logical%20Structure%20of%20Inter-universal%20Teichmuller%20Theory.pdf (修正箇所のリスト): https://www.kurims.kyoto-u.ac.jp/~motizuki/2021-04-15-ess-lgc-iut.txt ・Added an Introduction ・In \S 1.3, added "(UndIg)", as well as a reference to "(Undig)" in \S 2.1 ・Rewrote various portions of \S 1.5 ・Rewrote Example 2.4.4 ・Modified the title of Example 2.4.5 ・Added Example 2.4.6 ・Slightly modified the paragraph at the beginning of \S 3 ・Slightly modified the final portion of \S 3.1 concerning (FxRng), (FxEuc), (FxFld) ・Added Example 3.9.1 and made slight modifications to the surrounding text ・In \S 3.10, rewrote the discussion preceding (Stp1) ・In \S 3.11, slightly modified the discussion following ({\Theta}ORInd)
On the Essential Logical Structure of Inter-universal Teichmuller Theory in Terms of Logical AND "∧"/Logical OR "∨" Relations: Report on the Occasion of the Publication of the Four Main Papers on Inter-universal Teichmuller Theory.
2021年03月06日 ・(論文)宇宙際タイヒミューラー理論に関する論文4篇の出版を記念して、 新論文を掲載: On the Essential Logical Structure of Inter-universal Teichmuller Theory in Terms of Logical AND "∧"/Logical OR "∨" Relations: Report on the Occasion of the Publication of the Four Main Papers on Inter-universal Teichmuller Theory. 0107132人目の素数さん2021/04/17(土) 20:09:05.72ID:cr30r3uy>>106 追加
2021年04月15日 ・(論文)修正版を更新(修正箇所のリスト): On the Essential Logical Structure of Inter-universal Teichmuller Theory in Terms of Logical AND "∧"/Logical OR "∨" Relations: Report on the Occasion of the Publication of the Four Main Papers on Inter-universal Teichmuller Theory. 2021年01月15日 ・(論文)修正版を更新(修正箇所のリスト): 2021年03月06日 ・(論文)宇宙際タイヒミューラー理論に関する論文4篇の出版を記念して、 新論文を掲載: On the Essential Logical Structure of Inter-universal Teichmuller Theory in Terms of Logical AND "∧"/Logical OR "∨" Relations: Report on the Occasion of the Publication of the Four Main Papers on Inter-universal Teichmuller Theory. 2021年01月15日 ・(論文)修正版を更新(修正箇所のリスト): Combinatorial Construction of the Absolute Galois Group of the Field of Rational Numbers. 0108132人目の素数さん2021/04/17(土) 20:12:36.12ID:cr30r3uy>>105 >グロタン宇宙論もその類いで >昔の集合論の”U”(単なる全体集合)とは、意味が違うのです >そこらが、余計に混乱を招いているように思います
(補足) ・グロタン宇宙論を、いくつも作る? ・その複数のグロタン宇宙論の間を行ったり来たり? ・そこまで大袈裟な話でもなさそうに見えるけど(^^ 0109132人目の素数さん2021/04/25(日) 18:03:40.36ID:x2gQxWeEhttps://www.youtube.com/watch?v=a3nSruakVdw IUT overview: What papers are involved? Where does it start? Taylor Dupuy 20151217 In this video I give an overview of what papers are involved in Mochizuki's work on ABC. Hopefully this is useful to get a scope of things. 0110132人目の素数さん2021/05/01(土) 08:46:56.11ID:4gUFX+vb Inter-universal geometry と ABC予想 (応援スレ) 54 https://rio2016.5ch.net/test/read.cgi/math/1617170015/253 https://www.nikkei.com/article/DGXZQOCD251AC0V20C21A4000000/?unlock=1 数学の難問ABC予想 「証明」にも学界は冷ややか 2021年4月30日 11:00 [有料会員限定] 日経 (編集委員 青木慎一) 数学の世界では、時間がたってから証明が正しかったとわかることがある。例えば、ドイツのヒーグナーは1952年、史上最高の数学者といわれるガウスが予想した「類数問題」に関する証明を発表した。長い間無視されたが、60年代後半に複数の数学者がそれぞれ検討し、一部に問題があるものの本質的に正しかったと証明された。今は定理として名を残す。 (引用終り)
Contents 1 Gauss's original conjectures 2 Status 3 Lists of discriminants of class number 1 4 Modern developments 5 Real quadratic fields (引用終り) 以上 0113132人目の素数さん2021/05/09(日) 16:44:06.23ID:6xnjRD2Shttp://www.uvm.edu/~tdupuy/anabelian/VermontNotes_20.pdf KUMMER CLASSES AND ANABELIAN GEOMETRY Date: April 29, 2017. JACKSON S. MORROW
ABSTRACT. These notes comes from the Super QVNTS: Kummer Classes and Anabelian geometry. Any virtues in the notes are to be credited to the lecturers and not the scribe; however, all errors and inaccuracies should be attributed to the scribe. That being said, I apologize in advance for any errors (typo-graphical or mathematical) that I have introduced. Many thanks to Taylor Dupuy, Artur Jackson, and Jeffrey Lagarias for their wonderful insights and remarks during the talks, Christopher Rasmussen, David Zureick-Brown, and a special thanks to Taylor Dupuy for his immense help with editing these notes. Please direct any comments to jmorrow4692@gmail.com. The following topics were not covered during the workshop: ・ mono-theta environments ・ conjugacy synchronization ・ log-shells (4 flavors) ・ combinatorial versions of the Grothendieck conjecture ・ Hodge theaters ・ kappa-coric functions (the number field analog of etale theta) ´ ・ log links ・ theta links ・ indeterminacies involved in [Moc15a, Corollary 3.12] ・ elliptic curves in general position ・ explicit log volume computations CONTENTS 1. On Mochizuki’s approach to Diophantine inequalities Lecturer: Kiran Kedlaya . . 2 2. Why the ABC Conjecture? Lecturer: Carl Pomerance . 3 3. Kummer classes, cyclotomes, and reconstructions (I/II) Lecturer: Kirsten Wickelgren . 3 4. Kummer classes, cyclotomes, and reconstructions (II/II) Lecturer: David Zureick-Brown . 6 5. Overflow session: Kummer classes Lecturer: Taylor Dupuy . 8 6. Introduction to model Frobenioids Lecturer: Andrew Obus . 11 7. Theta functions and evaluations Lecturer: Emmanuel Lepage . . 13 8. Roadmap of proof Notes from an email from Taylor Dupuy . . 17 0114132人目の素数さん2021/07/05(月) 06:06:22.96ID:tA3B4T+Ihttps://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/244783/1/B76-02.pdf RIMS K?oky?uroku Bessatsu B76 (2019), 79?183 宇宙際 Teichm¨uller 理論入門 (Introduction to Inter-universal Teichm¨uller Theory) By 星 裕一郎 (Yuichiro Hoshi) P5 § 1. 円分物 数学 円分物とは何でしょうか. それは Tate 捻り “Zb(1)”のことです. (引用終り)
(参考:文字化けは面倒なので修正しませんので、原文ご参照) https://en.wikipedia.org/wiki/Tate_twist Tate twist In number theory and algebraic geometry, the Tate twist,[1] named after John Tate, is an operation on Galois modules.
For example, if K is a field, GK is its absolute Galois group, and ρ : GK → AutQp(V) is a representation of GK on a finite-dimensional vector space V over the field Qp of p-adic numbers, then the Tate twist of V, denoted V(1), is the representation on the tensor product V?Qp(1), where Qp(1) is the p-adic cyclotomic character (i.e. the Tate module of the group of roots of unity in the separable closure Ks of K). More generally, if m is a positive integer, the mth Tate twist of V, denoted V(m), is the tensor product of V with the m-fold tensor product of Qp(1). Denoting by Qp(?1) the dual representation of Qp(1), the -mth Tate twist of V can be defined as {\displaystyle V\otimes \mathbf {Q} _{p}(-1)^{\otimes m}.}{\displaystyle V\otimes \mathbf {Q} _{p}(-1)^{\otimes m}.} References [1] 'The Tate Twist', in Lecture Notes in Mathematics', Vol 1604, 1995, Springer, Berlin p.98-102 0116132人目の素数さん2021/07/05(月) 06:48:13.60ID:tA3B4T+I>>115 >Tate twist
下記が参考になりそう 日本語では、圧倒的に情報量が少ない それと”What is the intuition behind the concept of Tate twists?”と質問する姿勢は見習うべきでしょうね
1.Robertとか、woitとか、間違った人のサイトを見ても、間違った情報しかないと思うよ 2.それよか、IUTを読むための用語集資料スレ2 https://rio2016.5ch.net/test/read.cgi/math/1606813903/ に情報を集めているので、そこらも見てちょうだい 3.あと、下記を見る方が良いと思うよ 望月サイトのhttp://www.kurims.kyoto-u.ac.jp/~motizuki/ https://www.kurims.kyoto-u.ac.jp/~motizuki/papers-japanese.html 望月論文 講演のアブストラクト・レクチャーノート [1] 実複素多様体のセクション予想と測地線の幾何. PDF [2] p進Teichmuller理論. PDF [3] Anabelioidの幾何学. PDF [4] Anabelioidの幾何学とTeichmuller理論. PDF [5] 離散付値環のalmost etale extensions(学生用のノート). PDF [6] 数体と位相曲面に共通する「二次元の群論的幾何」(2012年8月の公開講座). PDF