Note that if mω+/ω > 1, then vphase is positive. It turns out that the energy flow down the hole, while always inward as seen locally, is determined by vphase for an observer at infinity. If mω+/ω > 1, energy flows out of the hole and the corresponding scattering wave mode is amplified, or “superradiantly scattered” (cf. Press and Teukolsky 1972, Misner 1972, and Zel’dovich 1972). A detailed discussion of electromagnetic and gravitational superradiance, including numerical values, will be given in a later paper in this series.
Note that if mω+/ω > 1, then vphase is positive. It turns out that the energy flow down the hole, while always inward as seen locally, is determined by vphase for an observer at infinity. If mω+/ω > 1, energy flows out of the hole and the corresponding scattering wave mode is amplified, or “superradiantly scattered” (cf. Press and Teukolsky 1972, Misner 1972, and Zel’dovich 1972). A detailed discussion of electromagnetic and gravitational superradiance, including numerical values, will be given in a later paper in this series.
Note that if mω+/ω > 1, then vphase is positive. It turns out that the energy flow down the hole, while always inward as seen locally, is determined by vphase for an observer at infinity. If mω+/ω > 1, energy flows out of the hole and the corresponding scattering wave mode is amplified, or “superradiantly scattered” (cf. Press and Teukolsky 1972, Misner 1972, and Zel’dovich 1972). A detailed discussion of electromagnetic and gravitational superradiance, including numerical values, will be given in a later paper in this series.
https://arxiv.org/pdf/2010.14293.pdf0360ご冗談でしょう?名無しさん2023/12/12(火) 22:25:23.54ID:4AX27uqC 例えば、 Can gravitational waves pass through a black hole? とか "gravitational wave" "event horizon" で検索すれば、わかりやすい回答が色々出てくる。
>v_phase = -k/ω = -1 + mω_+/ω >Note that if mω_+/ω > 1, then v_phase is positive
これは、位相速度が「外向き」になることがあると言っている。 ただし、その前で、
>v_group = -dk/dω = -1 >The group velocity agrees with condition (ii) above.
この(ii)というのは、
>Equivalently, way (ii) : demand that the radial group velocity of a wave packet, as measured by a physically well-behaved observer, be negative (i.e., signals can travel into the hole, but cannot come out).
The uniqueness of the modes’ frequencies and damping times is directly related to the ‘‘no-hair’’ theorem of general relativistic black holes, and thus a reliable detection and accurate identification of QNMs could provide the ‘‘smoking gun’’ for black holes and an important test of general relativity in the strong-field regime [3].