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Related papers: Comment to the CPT-symmetric Universe: Two possibl…

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A model of a two-sheeted universe in the quantum theory of gravity is proposed, based on the definition of 3D invariant and gauge-invariant proper time of the universe. A uniform time in a closed universe is introduced in the class of…

General Relativity and Quantum Cosmology · Physics 2025-11-17 Natalia Gorobey , Alexander Lukyanenko , A. V. Goltsev

We investigate the relationship between computation and spacetime structure, focussing on the role of closed timelike curves (CTCs) in promoting computational speedup. We note first that CTC traversal can be interpreted in two distinct…

General Relativity and Quantum Cosmology · Physics 2011-03-08 Mike Stannett

The concept of negative temperatures has occasionally been used in connection with quantum systems. A recent example of this sort is reported in the paper of S. Braun et al. [Science 339,52 (2013)], where an attractively interacting…

General Relativity and Quantum Cosmology · Physics 2013-10-01 Iver Brevik , Øyvind Grøn

We consider an evolution of anisotropic cosmological model on the example of the Bianchi type I homogeneous universe. It is filled by the mixture of matter and dark energy with an arbitrary barotropic equation of state (EoS). The general…

General Relativity and Quantum Cosmology · Physics 2023-06-14 S L Parnovsky

Cosmologists have developed a phenomenally successful picture of structure in the universe based on the idea that the universe expanded exponentially in its earliest moments. There are three pieces of evidence for this exponential expansion…

High Energy Physics - Phenomenology · Physics 2014-11-17 Scott Dodelson

Following the observational evidence for cosmic acceleration which may exclude a possibility for the universe to recollapse to a second singularity, we review alternative scenarios of its future evolution. Although the de Sitter asymptotic…

Astrophysics · Physics 2009-11-11 Mariusz P. Dabrowski

Recent works suggest that quantum theory may support a unification of the notions of space and time, thus treating the spatial and temporal quantum correlations equally. Specifically, the partial transposition of the maximally entangled…

High Energy Physics - Theory · Physics 2024-10-15 Ovidiu Racorean

The second law of thermodynamics is asymmetric with respect to time as it says that the entropy of the universe must have been lower in the past and will be higher in the future. How this time-asymmetric law arises from the time-symmetric…

Statistical Mechanics · Physics 2021-06-07 Sivapalan Chelvaniththilan

The standard interpretation of the observed redshifted spectra and luminosities towards distant astrophysical objects is that the universe is expanding, an inference which is found to be consistent with other cosmological probes as well.…

General Physics · Physics 2013-08-06 Meir Shimon

With CPT-invariant initial conditions that commute with CPT-invariant final conditions, the respective probabilities (when defined) of a set of histories and its CPT reverse are equal, giving a CPT-symmetric universe. This leads me to…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Don N. Page

Motivated by the lessons of black hole complementarity, we develop a causal patch description of eternal inflation. We argue that an observer cannot ascribe a semiclassical geometry to regions outside his horizon, because the large-scale…

High Energy Physics - Theory · Physics 2008-11-26 Raphael Bousso , Ben Freivogel , I-Sheng Yang

We disclose the thermodynamical properties of the apparent horizon in a nonsingular universe. We take into account the zero-point length correction to the gravitational potential and derive the modified entropy expression that includes…

General Relativity and Quantum Cosmology · Physics 2025-05-06 Ahmad Sheykhi , Leila Liravi , Kimet Jusufi

Phantom cosmology allows to account for dynamics and matter content of the universe tracing back the evolution to the inflationary epoch, considering the transition to the non-phantom standard cosmology (radiation/matter dominated eras) and…

High Energy Physics - Theory · Physics 2008-11-26 S. Capozziello , S. Nojiri , S. D. Odintsov

A cosmological scenario according to which our universe experienced space-time compactifications twice in its early development is investigated through toy models. In this scenario gauge configurations on an extra space play essential roles…

General Relativity and Quantum Cosmology · Physics 2015-02-25 Atsushi Nakamula , Kiyoshi Shiraishi

We discuss the evolution of the universe in the context of the second law of thermodynamics from its early stages to the far future. Cosmological observations suggest that most matter and radiation will be absorbed by the cosmological…

General Relativity and Quantum Cosmology · Physics 2013-04-03 Andrew P. Lundgren , Ruxandra Bondarescu , Mihai Bondarescu

Inflation is a bold and expansive extension of the Standard Cosmology. It holds the promise to extend our understanding of the Universe to within 10^{-32}sec of the big bang and answer most of the pressing questions in cosmology. Its…

Astrophysics · Physics 2007-05-23 Michael S. Turner

Based on the equivalence of the two different types of measurement protocols and the asymmetry between the Schr\"odinger and Heisenberg pictures, it has been previously proposed that negative sea fills the universe as a nondeterministic…

General Physics · Physics 2016-02-04 Daegene Song

This paper discusses the analytic continuation in the thermal field theory by using the theory of $\eta-\xi$ spacetime. Taking a simple model as example, the $2\times 2$ matrix real-time propagator is solved from the equation obtained…

High Energy Physics - Phenomenology · Physics 2007-05-23 Jian Zuo Yuan-Xing Gui

The emergent universe scenario was proposed to solve the big bang singularity by suggesting that the universe originates from an Einstein static state and then evolves into a subsequently inflationary era. Thus, to find the relic of the…

General Relativity and Quantum Cosmology · Physics 2022-11-01 Qihong Huang , Kaituo Zhang , Zhenxing Fang , Feiquan Tu

Non-minimally coupled scalar field models are well-known for providing interesting cosmological features. These include a late time dark energy behavior, a phantom dark energy evolution without singularity, an early time inflationary…

General Relativity and Quantum Cosmology · Physics 2021-09-03 Wompherdeiki Khyllep , Jibitesh Dutta