Related papers: Indefinite Information Processing in Ever-expandin…
We consider space-times with two isometries which represent gravitational waves with distinct wavefronts which propagate into exact Friedmann-Robertson-Walker (FRW) universes. The geometry of possible wavefronts is analysed in detail in all…
We investigate the evolution of the Universe filled with barotropic perfect fluid in Eddington-inspired Born-Infeld gravity. We consider both the isotropic and the anisotropic universe. At the early stage when the energy density is high,…
Thermodynamics is a macroscopic physical theory whose two very general laws are independent of any underlying dynamical laws and structures. Nevertheless, its generality enables us to understand a broad spectrum of phenomena in physics,…
We construct a model of a universe filled with a perfect fluid with isotropic particle pressure. The anisotropic plane symmetric Kasner spacetime is used as a seed metric and through a conformal mapping a perfect fluid is generated. The…
Geometry of the universe has always intrigued mathematicians and cosmologists. Recent results from the Wilkinson Microwave Anisotropy Project (WMAP) indicate that the visible universe is incredibly flat. This apparent flatness could be due…
The large-scale structure of the Universe is well approximated by the Friedmann equations, parametrized by several energy densities which can be observationally inferred. A natural question to ask is: How different would the Universe be if…
We observe the past and present of the universe, but can we predict the far future? Observations suggest that in thousands of billions of years from now most matter and radiation will be absorbed by the cosmological horizon. As it absorbs…
Gravitational waves (GWs) provide a powerful probe of the early universe due to their ability to free-stream across cosmic history. We study GW production in a compelling scenario where a rotating axion(-like) field becomes relevant for a…
We propose an interpretation of the expansion and acceleration of the Universe from an information theoretic viewpoint. We obtain the time evolution of the configuration entropy of the mass distribution in a static Universe and show that…
We study a universe filled with cold dark matter in the form of discrete inhomogeneities (e.g., galaxies) and dark energy in the form of a continuous perfect fluid. We develop a first-order scalar perturbation theory in the weak gravity…
We develop and examine the principles governing the formation of distortions in the cosmic microwave background. Distortions in the frequency or spectral distribution of the background probe the thermal history of the universe whereas those…
Adopting the Landau-Lifshiftz method of classical fluctuations we determine the statistical average strength of the fluctuations of the energy flux on the apparent horizon of a homogeneous and isotropic universe described by Einstein…
The Friedmann paradigm for a dynamical universe emanating from a spacetime singularity is critically reviwed. Quantum effects, playing the essential role at the very early stages, suggests that the universe may follow different course to…
We investigate the dynamics of the spatially flat universes submitted to isotropic tidal forces and adiabatic expansion under Einstein's equations. Surprisingly, the tendency to a high Hubble anisotropy at late times starts to appear as far…
We introduce "anamorphic" cosmology, an approach for explaining the smoothness and flatness of the universe on large scales and the generation of a nearly scale-invariant spectrum of adiabatic density perturbations. The defining feature is…
The accepted idea that the expansion of the universe is accelerating needs, for compatibility to general relativity, the introduction of some unusual forms of matter. However, several authors have proposed that instead of making weird…
It is argued that the observed Thermodynamic Arrow of Time must arise from the boundary conditions of the universe. We analyse the consequences of the no boundary proposal, the only reasonably complete set of boundary conditions that has…
Every physical measuring needs a finite, different from zero measurement time and provides information in form of the choice of a measurement result from all possible measurement results. If infinitely many (different) measurement results…
In an earlier work we showed that the gravitational interaction could be reproduced as a retarded dispersion interaction (Casimir interaction) between particles composed of hypothetical particles having harmonic oscillator interactions.…
We present a brief review on information processing, computing and inference via quantum fluctuation, and clarify the relationship between the probabilistic information processing and theory of quantum spin glasses through the analysis of…