51,639 research outputs found
Lorentz Transform of Black Body Radiation Temperature
The Lorentz transform of black body radiation has been investigated from the
view point of relativistic statistical mechanics. The result shows that the
well known expression with the directional temperature can be derived based on
the inverse temperature four vector. The directional temperature in the past
literature was the result of mathematical manipulation and its physical meaning
is not clear. The inverse temperature four vector has, in contrast, clear
meaning to understand relativistic thermodynamical processes.Comment: 6 pages, no figur
Three Views of a Secret in Relativistic Thermodynamics
It has been shown three different views in relativistic thermodynamics can be
derived from the basic formulation proposed by van Kampen and Israel. The way
to decompose energy-momentum into the reversible and irreversible parts is not
uniquely determined, and different choices result in different views. The
effect of difference in the definition of a finite volume is also considered.Comment: 4 pages, no figure
Second Order Gauge Invariant Perturbation Theory -- Perturbative curvatures in the two-parameter case --
Based on the gauge invariant variables proposed in our previous paper [K.
Nakamura, Prog. Theor. Phys. vol.110 (2003), 723.], some formulae of the
perturbative curvatures of each order are derived. We follow the general
framework of the second order gauge invariant perturbation theory on arbitrary
background spacetime to derive these formulae. These perturbative curvatures do
have the same form as the definitions of gauge invariant variables for
arbitrary perturbative fields which are previously proposed. As a result, we
explicitly see that any perturbative Einstein equations are given in terms of
gauge invarinat form. We briefly discuss physical situations to which this
framework should be applied.Comment: 31 pages, 1 figure, PTPTEX (ptptex.cls ver 0.9);Some typos in the
published version are correcte
Gauge-invariant variables in general-relativistic perturbations: globalization and zero-mode problem
An outline of a proof of the local decomposition of linear metric
perturbations into gauge-invariant and gauge-variant parts on an arbitrary
background spacetime is briefly explained. We explicitly construct the
gauge-invariant and gauge-variant parts of the linear metric perturbations
based on some assumptions. We also point out the zero-mode problem is an
essential problem to globalize of this decomposition of linear metric
perturbations. The resolution of this zero-mode problem implies the possibility
of the development of the higher-order gauge-invariant perturbation theory on
an arbitrary background spacetime in a global sense.Comment: (v1) 16 pages, no figure; (v2) 9 pages, no figure. Compactified for
"2012 Awards for Essays on Gravitation" promoted by Gravity Research
Foundation. References are deleted. no ingredients is changed. This version
received Honorable Mention for 201
- …