THERMODYNAMIC PROPERTIES OF $\gamma$--FLUIDS AND THE QUANTUM VACCUM

Abstract

The thermodynamic behaviour of a relativistic perfect simple fluid obeying the equation of state $p=(\gamma -1)\rho$, where $0\le \gamma \le 2$ is a constant, has been investigated. Particular cases include: vacuum($p=-\rho$, $\gamma =0$), a randomly oriented distribution of cosmic strings ($p=-\frac{1}{3}\rho$, $\gamma =2/3$), blackbody radiation ($p=\frac{1}{3}\rho$, $\gamma =4/3$) and stiff matter ($p=\rho$, $\gamma =2$). Fluids with $\gamma <1$ become hotter when they expand adiabatically ($T\propto V^{1-\gamma }$). By assuming that such fluids may be regarded as a kind of generalized radiation, the general Planck's type form of the spectrum is deduced. As a limiting case, a new Lorentz invariant spectrum of the vacuum which is compatible with the equation of state and other thermodynamic constraints is proposed. Some possible consequences to the early universe physics are also discussed.

20 pages, uses LATEX

References in corpus (1)

• Zeta Functions and the Casimir Energy

Cited by in corpus (28)

• Cosmic anti-friction and accelerated expansion
• Phantom thermodynamics
• Accelerating Cold Dark Matter Cosmology (${\Omega }_{\Lambda }\equiv 0$)
• Thermodynamics, Spectral Distribution and the Nature of Dark Energy
• Cosmological particle production, causal thermodynamics, and inflationary expansion
• Thermodynamical properties of the Universe with dark energy
• Dynamical Vacuum in Quantum Cosmology
• On Phantom Thermodynamics
• Collisional equilibrium, particle production and the inflationary universe
• Thermodynamical properties of dark energy
• Two-Fluid Atmosphere for Relativistic Stars
• Chemical Potential and the Nature of the Dark Energy: The case of phantom
• Isotropic cases of static charged fluid spheres in general relativity
• Clustering, Angular Size and Dark Energy
• On phantom thermodynamics with negative temperature
• Thermodynamics of phantom energy in the presence of a Reissner-Nordstrom black hole
• Inflation in a self-interacting gas universe
• Wormholes, Classical Limit and Dynamical Vacuum in Quantum Cosmology
• Qualitative study of perfect-fluid Friedmann-Lema\^ıtre-Robertson-Walker models with a cosmological constant
• Phantom Accretion by Black Holes and the Generalized Second Law of Thermodynamics
• Compressible Fluids with Maxwell-type equations, the minimal coupling with electromagnetic field and the Stefan-Boltzmann law
• Thermodynamics of the Primordial Universe
• Cosmological constant in a quantum fluid model
• Generalised equilibrium of cosmological fluids in second-order thermodynamics
• Semiclassical Effects in Color Flavor Locked Strange Stars
• Eckart heat-flux applicability in $F(\Phi ,X)R$ theories and the existence of temperature gradients
• Equivalence between generalized phenomenological schemes for the interaction of cosmological fluids: applications to arbitrary linear barotropic fluids and vacuum decay
• Generalized Semi-Holographic Universe