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Related papers: Off-Diagonal Metrics and Anisotropic Brane Inflati…

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We present a non-compact (4 + 1) dimensional model with a local strong four-fermion interaction supplementing it with gravity. In the strong coupling regime it reveals the spontaneous translational symmetry breaking which eventually leads…

High Energy Physics - Theory · Physics 2011-07-19 A. A. Andrianov , V. A. Andrianov , P. Giacconi , R. Soldati

We review the theoretical implications of the past decade of CMB anisotropy measurements, which culminated in the recent detection of the first feature in the power spectrum, and discuss the tests available to the next decade of…

Astrophysics · Physics 2007-05-23 Wayne Hu

We analyze the possibility of global anisotropy of the universe. We consider an altered Friedmann Lemaitre Robertson Walker metric in which there are different scale factors along the three different axes of space. We construct the…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-06 Mark P. Hertzberg , Abraham Loeb

General model of multidimensional $R^2$-gravity including Riemann tensor square term (non-zero $c$ case) is considered. The number of brane-worlds in such model is constructed (mainly in five dimensions) and their properties are discussed.…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov , Sachiko Ogushi

Using our anholonomic frame deformation method, we show how generic off-diagonal cosmological solutions depending, in general, on all spacetime coordinates and undergoing a phase of ultra-slow contraction can be constructed in massive…

High Energy Physics - Theory · Physics 2017-06-05 Sergiu I. Vacaru

We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a $U(1)$ gauge field. Primordial anisotropies are generated either actively during inflation or from…

High Energy Physics - Theory · Physics 2015-06-17 Ali Akbar Abolhasani , Razieh Emami , Hassan Firouzjahi

The combination of detections of anisotropy in the Cosmic Microwave Background radiation and observations of the large-scale distribution of galaxies probes the primordial density fluctuations of the universe on spatial scales varying by…

Astrophysics · Physics 2008-11-26 Eric Gawiser , Joseph Silk

Observations of the extragalactic radio background have uncovered a significant isotropic emission across multiple frequencies spanning from 22 MHz to 10 GHz. The intensity of this non-thermal emission component significantly exceeds the…

High Energy Astrophysical Phenomena · Physics 2016-07-05 Ke Fang , Tim Linden

Many models of the early universe predict that there should be primordial tensor perturbations. These leave an imprint into the temperature and polarisation anisotropies of the cosmic microwave background (CMB). The differential equation…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-04 Darsh Kodwani , P. Daniel Meerburg , Ue-Li Pen , Xin Wang

In the first stages of inflationary reheating, the temperature of the radiation produced by inflaton decays is typically higher than the commonly defined reheating temperature $T_{RH} \sim (\Gamma_\phi M_P)^{1/2}$ where $\Gamma_\phi$ is the…

High Energy Physics - Phenomenology · Physics 2017-11-22 Marcos A. G. Garcia , Yann Mambrini , Keith A. Olive , Marco Peloso

The existence of a large primordial neutrino asymmetry is an intriguing possibility, both observationally and theoretically. Such an asymmetry can lead to the resonant production of $\mathrm{keV}$-scale sterile neutrinos, which are a…

High Energy Physics - Phenomenology · Physics 2025-10-08 Kentaro Kasai , Masahiro Kawasaki , Kai Murai

Possible signatures of primordial magnetic fields on the Cosmic Microwave Background (CMB) temperature and polarization anisotropies are reviewed. The signals that could be searched for include excess temperature anisotropies particularly…

Astrophysics · Physics 2009-11-11 Kandaswamy Subramanian

We consider an anisotropic brane world with Bianchi type I and V geometries where the mechanism of confining the matter on the brane is through the use of a confining potential. The resulting equations on the anisotropic brane are modified…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Heydari-Fard , H. R. Sepangi

We asses the contribution to the observed large scale anisotropy of the cosmic microwave background radiation, arising from both gravity waves as well as adiabatic density perturbations, generated by a common inflationary mechanism in the…

High Energy Physics - Phenomenology · Physics 2009-10-22 Tarun Souradeep , Varun Sahni

Dark matter may be coupled to dark radiation: light degrees of freedom that mediate forces between dark sector particles. Cosmological constraints favor dark radiation that is colder than Standard Model radiation. In models with fixed…

High Energy Physics - Phenomenology · Physics 2016-10-12 Matthew Reece , Thomas Roxlo

We present an effective Eulerian description, in the non-relativistic regime, of the growth of cosmological perturbations around a homogeneous but anisotropic Bianchi I spacetime background. We assume a small deviation from isotropy,…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-10 Juan P. Beltrán Almeida , Josué Motoa-Manzano , Jorge Noreña , Thiago S. Pereira , César A. Valenzuela-Toledo

The role of conformal anomaly in AdS/CFT and related issues is clarified. The comparison of holographic and QFT conformal anomalies (with account of brane quantum gravity contribution) indicates on the possibility for brane quantum gravity…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov

We investigate the off-diagonal sector of eigenstate thermalization using both local and non-local probes in 2-dimensional conformal field theories. A novel analysis of the asymptotics of OPE coefficients via the modular bootstrap is…

High Energy Physics - Theory · Physics 2019-01-02 Enrico M. Brehm , Diptarka Das , Shouvik Datta

The asymptotic behavior of metric perturbations in Randall-Sundrum infinite brane world is carefully investigated. Perturbations generated by matter fields on the brane are shown to be regular even at the future Cauchy horizon.

High Energy Physics - Phenomenology · Physics 2008-11-26 Takahiro Tanaka

The cosmic microwave background (CMB) anisotropies have turned out to represent one of the most stringent 'bottle necks' for scenarios of large scale structure formation. As a possibility to relax this constraint, it has been proposed that…

Astrophysics · Physics 2009-10-22 Ruth Durrer