English
Related papers

Related papers: Puzzling initial conditions in the R_h=ct model

200 papers

Quantum field theory, which is generally used to describe the origin of large-scale gravitational perturbations during cosmic inflation, has been shown to omit an important physical effect in curved space-time, the nonlocal entanglement…

General Relativity and Quantum Cosmology · Physics 2022-04-01 Craig Hogan

Although cosmological observations suggest that the fluctuations of seed fields are almost Gaussian, the possibility of a small deviation of their fields from Gaussianity is widely discussed. Theoretically, there exist numerous inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Maresuke Shiraishi

Fluctuations in the cosmic microwave background (CMB) temperature are being studied with ever increasing precision. Two competing types of theories might describe the origins of these fluctuations: ``inflation'' and ``defects''. Here we…

Astrophysics · Physics 2010-04-08 Andreas Albrecht , David Coulson , Pedro Ferreira , Joao Magueijo

An inhomogeneous cosmological magnetic field creates vortical perturbations that survive Silk damping on much smaller scales than compressional modes. This ensures that there is no sharp cut-off in anisotropy on arc-minute scales. As we had…

Astrophysics · Physics 2009-11-07 Kandaswamy Subramanian , John D. Barrow

Spectrum of initial scalar and tensor perturbations created during an inflationary stage producing a closed or open FRW universe now is discussed. In the closed case, the CMB temperature anisotropy ${\Delta T/T}$ generated by scalar…

Astrophysics · Physics 2007-05-23 A. A. Starobinsky

As previously discussed in (D. Sudarsky, Int.J.Mod.Phys.D20:509-552, (2011); [arXiv:0906.0315]), the inflationary account for the emergence of the seeds of cosmic structure falls short of actually explaining the generation of primordial…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Pedro Cañate , Philip Pearle , Daniel Sudarsky

We describe the subject of Cosmic Microwave Background (CMB) analysis - its past, present and future. The theory of Gaussian primary anisotropies, those arising from linear physics operating in the early Universe, is in reasonably good…

Astrophysics · Physics 2010-05-12 J. Richard Bond , Robert G. Crittenden

We theoretically and observationally investigate different choices of initial conditions for the primordial mode function that are imposed during an epoch preceding inflation. By deriving predictions for the observables resulting from…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-23 T. Gessey-Jones , W. J. Handley

Collisions between cosmic bubbles of different vacua are a generic feature of false vacuum eternal inflation scenarios. While previous studies have focused on the consequences of a single collision event in an observer's past, we begin here…

High Energy Physics - Theory · Physics 2013-05-30 Jonathan Kozaczuk , Anthony Aguirre

The ten's of micro-Kelvin variations in the temperature of the cosmic microwave background (CMB) radiation across the sky encode a wealth of information about the Universe. The full-sky, high-resolution maps of the CMB that will be made in…

Astrophysics · Physics 2007-05-23 Martin White

We review why the search for a causal explanation of the large scale properties of the universe supports the idea that an extended period of accelerated expansion, called inflation, preceded primordial nucleosynthesis. As a consequence of…

Astrophysics · Physics 2011-01-28 Parentani Renaud

Phase transitions in the early universe can readily create an observable stochastic gravitational wave background. We show that such a background necessarily contains anisotropies analogous to those of the cosmic microwave background (CMB)…

High Energy Physics - Phenomenology · Physics 2019-08-06 Michael Geller , Anson Hook , Raman Sundrum , Yuhsin Tsai

We explore the hemispherical asymmetry predicted in cosmic microwave background polarization when there is an asymmetry in temperature anisotropies due to primordial perturbations. We consider the cases of asymmetries due to adiabatic and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 M. H. Namjoo , A. A. Abolhasani , H. Assadullahi , S. Baghram , H. Firouzjahi , D. Wands

Several accurate analyses of the CMB temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed a set of anomalous results, at large angular scales, that appears inconsistent with the statistical isotropy expected…

Astrophysics · Physics 2009-07-22 A. Bernui , W. S. Hipolito-Ricaldi

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. Proposals that invoke some form of initial…

General Relativity and Quantum Cosmology · Physics 2016-01-12 Pisin Chen , Yu-Hsiang Lin

The damping of primordial perturbations at small scales gives rise to distortions of the cosmic microwave background (CMB). Here, the dependence of the distortion on the different types of cosmological initial conditions is explored,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-18 Jens Chluba , Daniel Grin

We investigate the degree to which the Cosmic Microwave Background (CMB) can be used to constrain primordial non-Gaussianity coming from the presence of spinning particles coupled to the inflaton. We compute the $\langle TTT \rangle$ and…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-09 Lorenzo Bordin , Giovanni Cabass

In inflationary models with minimal amount of gravity waves, the primordial power spectrum of density fluctuations, $A_S^2(k)$, together with the basic cosmological parameters, completely specify the predictions for the cosmic microwave…

Astrophysics · Physics 2009-10-31 Yun Wang , David N. Spergel , Michael A. Strauss

Measurements of the cosmic microwave background (CMB) radiation provide a unique opportunity for a direct study of the primordial cosmic plasma at redshift z ~1000. The angular power spectra of temperature and polarisation fluctuations are…

Astrophysics · Physics 2009-11-10 Marco Bersanelli , Davide Maino , Aniello Mennella

The anisotropy study cosmic microwave background (CMB) is one of the main observational tools for modern cosmology. However, alongside the study of the thermal fluctuations of the CMB are other equally important information, which is known…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-18 Alexander Bonilla Rivera
‹ Prev 1 8 9 10 Next ›