Abstract

We derive a general exact form of the phase space distribution function and the thermal expectation values of local operators for the free quantum scalar field at equilibrium with rotation and acceleration in flat space-time without solving field equations in curvilinear coordinates. After factorizing the density operator with group theoretical methods, we obtain the exact form of the phase space distribution function as a formal series in thermal vorticity through an iterative method and we calculate thermal expectation values by means of analytic continuation techniques. We separately discuss the cases of pure rotation and pure acceleration and derive analytic results for the stress-energy tensor of the massless field. The expressions found agree with the exact analytic solutions obtained by solving the field equation in suitable curvilinear coordinates for the two cases at stake and already — or implicitly — known in literature. In order to extract finite values for the pure acceleration case we introduce the concept of analytic distillation of a complex function. For the massless field, the obtained expressions of the currents are polynomials in the acceleration/temperature ratios which vanish at 2π, in full accordance with the Unruh effect.

Highlights

  • T0 being the temperature and μ0 the chemical potential coupled to a conserved charge Q, and Z the partition function

  • The presented derivation does not make use of the solutions of the Klein-Gordon equations in curvilinear coordinates but it is just based on the plane wave expansion of the field in Minkowski space-time and it is suitable for the general case including both rotation and linear acceleration

  • We have studied the series in two major cases of non-trivial equilibrium, the pure acceleration and the pure rotation and compared with exact known results obtained solving Klein-Gordon equation in Rindler and rotating coordinates respectively

Read more

Summary

Thermal expectation values of annihilation and creation operators

The building block to calculate any statistical quantity (mean values, correlations) is the mean value of the combination of one creation and one annihilation operator of four-momentum eigenstates: Tr ρ a†(p) a(p ). Before setting out to do that, it should be first pointed out that any other combination of creation or annihilation operators, such as a†(p) a†(p ) , a(p) a(p ) or combination of creation/annihilation operators of particles and antiparticles in case of a charged scalar field, will vanish. This happens because the density operator (1.2), involving just the generators of Lorentz transformation, translations and charge, does not change the number of particles and antiparticles.

Factorization of the density operator
Iterative solution with imaginary
The covariant Wigner function and the phase space distribution function
Properties of the distribution function
Mathematical interlude: analytic distillation and series resummation
Study of the series and comparison with known results: acceleration
Distillation and comparison with known results
Study of the series and comparison with known results: rotation
Comparison with known results
Thermodynamic equilibrium with rotation and acceleration: a new result
Summary
A Recurrence formula
B Solutions of the homogeneous equation
C Analytic distillation for pure acceleration and the Unruh effect
D Stress-energy tensor for a massless scalar field in Rindler coordinates
E Analytic distillation of the stress-energy tensor for pure rotation
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call