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Related papers: CPT Symmetry in Projective de Sitter Universes

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Observations of the cosmic microwave sky are revealing the primordial non-uniformities from which all structure in the Universe grew. The only known physical mechanism for generating the inhomogeneities we see involves the amplification of…

Astrophysics · Physics 2009-10-31 Neil Turok

It is fair to say that the deepest mystery in our understanding of nature is the birth of our universe. Much of the dilemma over the last decades comes from the extraordinarily small probability that the universe started with the high…

High Energy Physics - Theory · Physics 2008-09-25 Laura Mersini-Houghton

In the standard inflationary paradigm the inhomogeneities observed in the CMB arise from quantum fluctuations of an initially homogeneous and isotropic vacuum state. This picture suffers from two well-known weaknesses. First, it assumes…

General Relativity and Quantum Cosmology · Physics 2026-01-21 Gabriel R. Bengochea , Gabriel Leon , Alejandro Perez

There is an apparent power deficit relative to the Lambda-CDM prediction of the CMB spectrum at large scales, which, though not yet statistically significant, persists from WMAP to Planck data. We first present a simple toy model…

General Relativity and Quantum Cosmology · Physics 2017-10-31 Yu-Hsiang Lin

The cosmology of "Spontaneous Creation of the Universe Ex Nihilo" and the cosmology of the Symmetrical Relativity offer proposals to explain the creation and evolution of the universe. In essence they are still very distinct. However, we…

General Physics · Physics 2020-10-16 Cláudio Nassif Cruz , Fernando Antônio da Silva

We propose a simple phenomenological model predicting, through Lorentz symmetry breaking, a CPT-violating asymmetry between particle and antiparticle states in neutrino oscillations involving sterile neutrinos. Such a model is able to…

High Energy Physics - Phenomenology · Physics 2014-11-20 S. Esposito , G. Salesi

We consider the quantum birth of a hot FRW universe from a vacuum-dominated quantum fluctuation with admixture of radiation and strings, which correspond to quantum tunnelling from a discrete energy level with a non-zero temperature. The…

General Relativity and Quantum Cosmology · Physics 2007-05-23 I. G. Dymnikova , M. L. Fil'chenkov

We study the paradoxical aspects of closed time-like curves and their impact on the theory of computation. After introducing the $\text{TM}_\text{CTC}$, a classical Turing machine benefiting CTCs for backward time travel, Aaronson et al.…

Computational Complexity · Computer Science 2023-01-30 Sara Babaee Khanehsar , Farzad Didehvar

Many studies have been carried out since T.Padmanabhan proposed that the cosmic acceleration can be understood from the perspective that spacetime dynamics is an emergent phenomenon. Motivated by such a new paradigm, we firstly study the de…

General Relativity and Quantum Cosmology · Physics 2015-08-05 Zi-Liang Wang , Wen-Yuan Ai , Hua Chen , Jian-Bo Deng

This paper investigates Starobinsky's model of inflation driven by the trace anomaly of conformally coupled matter fields. This model does not suffer from the problem of contrived initial conditions that occurs in most models of inflation…

High Energy Physics - Theory · Physics 2009-10-31 S. W. Hawking , T. Hertog , H. S. Reall

Invariance under the combined transformations of CPT (in any order) is guaranteed in Quantum Field Theory in flat space times due to a basic theorem (CPT Theorem). The currently used formalism of particle physics phenomenology is based on…

High Energy Physics - Phenomenology · Physics 2007-05-23 Nick E. Mavromatos

Decoherence has the potential to explain all existing neutrino data including LSND results, without enlarging the neutrino sector. This particular form of CPT violation can preserve the equality of masses and mixing angles between particle…

High Energy Physics - Phenomenology · Physics 2009-11-10 Gabriela Barenboim , Nick Mavromatos

Coherent states consist of superposition of infinite number of particles and do not have a classical analogue. We study their evolution in a FLRW cosmology and show that only when full quantum corrections are considered, they may survive…

High Energy Physics - Phenomenology · Physics 2015-08-26 Houri Ziaeepour

The early Universe inflation is well known as a promising theory to explain the origin of large scale structure of the Universe, a causal theory for the origin of primordial density fluctuations which may explain the observed density…

Astrophysics · Physics 2007-05-23 Xin-he Meng

The solution for an inflationary universe without singularities is derived from the Einstein-Lemaitre equations. The present state of the universe evolved from a steady state solution for a tiny, but classical micro-universe with large…

Astrophysics · Physics 2007-05-23 E. Rebhan

We consider chaotic inflation in the theories with the effective potentials phi^n and e^{\alpha\phi}. In such theories inflationary domains containing sufficiently large and homogeneous scalar field \phi permanently produce new inflationary…

General Relativity and Quantum Cosmology · Physics 2009-09-29 Andrei Linde , Dmitri Linde , Arthur Mezhlumian

We study some gravitational instanton solutions that offer a natural realization of the spontaneous creation of inflationary universes in the brane world context in string theory. Decoherence due to couplings of higher (perturbative) modes…

High Energy Physics - Theory · Physics 2009-11-10 Hassan Firouzjahi , Saswat Sarangi , S. -H. Henry Tye

Describing dynamics in a gravitational universe with positive cosmological constant, such as de Sitter space, is a conceptually challenging problem. We propose a principle for constructing a quantum system that can potentially be used to…

High Energy Physics - Theory · Physics 2026-05-07 Vladimir Narovlansky

In this letter, we outline an inhomogeneous model of the Big Bang cosmology. For the inhomogeneous spacetime used here, the universe originates in the infinite past as the one dominated by vacuum energy and ends in the infinite future as…

Astrophysics · Physics 2007-05-23 Sanjay M. Wagh

We are at a specific period of modern cosmology, during which the large increase of the amount of data leads to the idea that the determination of cosmological parameters has been achieved with a rather good precision. There is a large…

Astrophysics · Physics 2017-08-23 A. Blanchard
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