4,622 research outputs found
Uniform asymptotics for the incomplete gamma functions starting from negative values of the parameters
We consider the asymptotic behavior of the incomplete gamma functions
gamma(-a,-z) and Gamma(-a,-z) as a goes to infinity. Uniform expansions are
needed to describe the transition area z~a in which case error functions are
used as main approximants. We use integral representations of the incomplete
gamma functions and derive a uniform equation by applying techniques used for
the existing uniform expansions for gamma(a,z) and Gamma(a,z). The result is
compared with Olver's uniform expansion for the generalized exponential
integral. A numerical verification of the expansion is given in a final
section
High-temperature expansion of the one-loop free energy of a scalar field on a curved background
The complete form of the high-temperature expansion of the one-loop
contribution to the free energy of a scalar field on a stationary gravitational
background is derived. The explicit expressions for the divergent and finite
parts of the high-temperature expansion in a three-dimensional space without
boundaries are obtained. These formulas generalize the known one for the
stationary spacetime. In particular, we confirm that for a massless conformal
scalar field the leading correction to the Planck law proportional to the
temperature squared turns out to be nonzero due to non-static nature of the
metric. The explicit expression for the so-called energy-time anomaly is found.
The interrelation between this anomaly and the conformal (trace) anomaly is
established. The natural simplest Lagrangian for the "Killing vector field" is
given.Comment: 27 pages;considerable changes made,appendix B changed,equation (52)
changed abstract changed, conclusion added, some references adde
- β¦