Related papers: How hot are expanding universes ?
Thermalization is the process through which a physical system evolves toward a state of thermal equilibrium. Determining whether or not a physical system will thermalize from an initial state has been a key question in condensed matter…
We construct a model for the universe based on the existence of quantum fields at finite temperature in the background of Robertson-Walker spacetime in presence of a non-zero cosmological constant. We discuss the vacuum regime in the light…
Our fundamental theories, i.e., the quantum theory and general relativity, are invariant under time reversal. Only when we treat system from the point of view of thermodynamics, i.e., averaging between many subsystem components, an arrow of…
It is possible to associate temperatures with the non-extremal horizons of a large class of spherically symmetric spacetimes using periodicity in the Euclidean sector and this procedure works for the de Sitter spacetime as well. But, unlike…
It is argued that the previously proposed modification of the standard (flat) inflationary $\Lambda CDM$ model in which cosmological constant is replaced by thermal energy of expanding vacum, characterized by the Gibbons-Hawking…
It has been proved in the context of quantum fields in Minkowski spacetime that the vacuum state is a thermal state according to uniformly accelerated observers -- a seminal result known as the Unruh effect. Recent claims, however, have…
One of the major open problems in theoretical physics is a consistent quantum gravity theory.Recent developments in thermodynamic phase transitions ofblack holes and their van der Waals-like behavior may provide an interesting quantum…
We study the Unruh effect for an observer with a finite lifetime, using the thermal time hypothesis. The thermal time hypothesis maintains that: (i) time is the physical quantity determined by the flow defined by a state over an observable…
This document explores the potential of quantum computing in Thermal Science. Conceived as a living document, it will be continuously updated with experimental findings and insights for the research community in Thermal Science. By…
To optimally utilize all the exciting cosmological data coming in we need to sharpen also the theoretical tools available to cosmologists. One such indispensible tool to understand hot big bang cosmology is finite temperature field theory.…
In this work we suggest a sufficiently simple for understanding "without knowing the details of the quantum gravity" and quite correct deduction of the Unruh temperature (but not whole Unruh radiation process!). Firstly, we shall directly…
By following the spirit of arXiv:1003.5665, we define a new Tolman temperature of Kodama observer directly related to its acceleration. We give a generalized integral form of thermodynamics relation on virtual sphere of constant $r$ in…
The dynamics of the expanding universe is analyzed in terms of the quantum geometrodynamical model. It is shown that the equations of quantum theory in the form of the eigenvalues equation similar to the stationary Schr\"{o}dinger equation…
We perform the thermal Renormalization Group (RG) study of the Asymptotically Safe (AS) quantum gravity in the Einstein-Hilbert truncation by relating the temperature parameter to the running RG scale as $T \equiv k_T = \tau k$ (in natural…
We investigate the quantum field aspects in flat spacetime for an uniformly accelerated observer moving in a thermal bath. In particular, we obtain an exact closed expression of the reduced density matrix for an uniformly accelerated…
From an extended relativistic dynamics for a particle moving in a cosmic background field with temperature T, we aim to obtain the speed of light with an explicit dependence on the background temperature of the universe. Although finding…
Reasonable parametrizations of the current Hubble data set of the expansion rate of our homogeneous and isotropic universe, after suitable smoothing of these data, strongly suggests that the area of the apparent horizon increases…
For a rather general class of scenarios, sweeping through a zero-temperature phase transition by means of a time-dependent external parameter entails universal behavior: In the vicinity of the critical point, excitations behave as quantum…
Thermodynamics provides a useful interpretation of scalar-tensor gravity, in which the effective imperfect fluid admitted by the nonminimal coupling features a temperature that is associated with the departure from general relativity.…
Relativistic thermodynamics is constructed from the point of view of special relativistic hydrodynamics. A relativistic four-current for heat and a general treatment of thermal equilibrium between moving bodies is presented. The different…