New answers tagged spacetime-dimensions
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What does Backward Time Factor mean physically?
We consider a time boundary at $t=0$ separating two regions with permittivities $\epsilon_1$ ($t<0$) and $\epsilon_2$ ($t>0$) in a one-dimensional, non-dispersive medium with constant ...
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Equivalence of Hawking Temperature Between Black Hole and its KK Reduction
The apparent discrepancy in the redshift factor $V$, and thus the Hawking temperature $T_H$, arises from an incomplete identification of the appropriate Killing vector in the 3+1 dimensional theory ...
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How does the lifetime and temperature of a black hole scale with mass in universe with more then 3 spacial dimensions?
Consider a Schwarzschild black hole in $d\ge3$ space dimensions. Write power laws as $X\propto M^{\left[X\right]}$. The Schwarzschild radius $R$, Hawking temperature $T$, surface gravity $g$, rate of ...
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How to dimensionally reduce the 3+1D Dirac equation into the 1+1D Dirac equation?
The method suggested by @Qmechanic. It can be done in three lines.
The 4-component Dirac equation can be re-written as
$$
i\partial_t \psi = \left [ \gamma^0 \gamma^{a} (-i\nabla_a) + \gamma^0 m \...
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