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Related papers: Causality and the Power Spectrum

200 papers

The pattern of acoustic peaks in the sub-horizon power spectrum of primordial density anisotropies at recombination can be naturally understood in the framework of standard Friedmann-Robertson-Walker cosmology (without inflation) as a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 David H. Oaknin

Scaling arguments are used to constrain the angular spectrum of distortions on boundaries of macroscopic causal diamonds, produced by Planck-scale vacuum fluctuations of causally-coherent quantum gravity. The small-angle spectrum of…

General Relativity and Quantum Cosmology · Physics 2024-07-02 Craig Hogan , Ohkyung Kwon , Nathaniel Selub

We provide a unified description of the hemispherical asymmetry in the cosmic microwave background generated by the mechanism proposed by Erickcek, Kamionkowski, and Carroll, using a delta N formalism that consistently accounts for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Takeshi Kobayashi , Marina Cortês , Andrew R. Liddle

We study the growth of linear perturbations induced by a generic causal scaling source as a function of the cosmological parameters $h$, $\Omega^m_0$ and $\Omega^\Lambda_0$. We show that for wavenumbers $k \gsim 0.01 h/Mpc$ the spectrum of…

Astrophysics · Physics 2009-10-31 P. P. Avelino , J. P. M. de Carvalho

The low energy mass spectrum of QCD in the large $N_C$ limit is computed. The low-lying states in the meson spectrum are explicitly evaluated up to the fourth order in the strong coupling perturbative expansion. The 't Hooft limit is smooth…

High Energy Physics - Lattice · Physics 2009-11-10 G. Grignani , D. Marmottini , P. Sodano

Non-inflationary sources of gravitational waves in the early Universe generically predict causality-limited tensor power spectra at low frequencies. We report the first-ever constraints on such sources based on cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-30 Jessica A. Zebrowski , Aurora Ireland , Christian L. Reichardt , Kylar Greene , Gordan Krnjaic , Yuhsin Tsai , François R. Bouchet

We present evidence that the simplest particle-physics scalar-field models of dynamical dark energy can be separated into distinct behaviors based on the acceleration or deceleration of the field as it evolves down its potential towards a…

Astrophysics · Physics 2008-11-26 R. R. Caldwell , Eric V. Linder

It has been argued that the power spectrum of the anisotropies in the Cosmic Microwave Background (CMB) may be effectively degenerate, namely that the observable spectrum does not determine a unique set of cosmological parameters. We…

Astrophysics · Physics 2015-06-24 R. Benton Metcalf , Joseph Silk

The Cosmic Defect theory has been confronted with four observational constraints: primordial nuclear species abundances emerging from the big bang nucleosynthesis; large scale structure formation in the universe; cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 N. Radicella , M. Sereno , A. Tartaglia

Imagine a scenario in which the dark energy forms via the condensation of dark matter at some low redshift. The Compton wavelength therefore changes from small to very large at the transition, unlike quintessence or metamorphosis. We study…

Astrophysics · Physics 2009-11-07 Bruce A. Bassett , Martin Kunz , David Parkinson , Carlo Ungarelli

The concentrations of the cuspy dark matter halos predicted by simulations of cold dark matter are related to the cosmology in which the halos form. Observational constraints on halo concentration therefore map into constraints on…

Astrophysics · Physics 2009-11-07 S. McGaugh , M. Barker , E. de Blok

If the hemispherical power asymmetry observed in the cosmic microwave background (CMB) on large angular scales is attributable to a superhorizon curvaton fluctuation, then the simplest model predicts that the primordial density fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Adrienne L. Erickcek , Christopher M. Hirata , Marc Kamionkowski

The ARCADE2 and LWA1 experiments have claimed an excess over the Cosmic Microwave Background (CMB) at low radio frequencies. If the cosmological high-redshift contribution to this radio background is between 0.1% and 22% of the CMB at 1.42…

The latest analysis of the cosmic microwave background by the Planck team finds more smoothing of the acoustic peaks in the temperature power spectrum than predicted by $\Lambda$CDM. Here we investigate whether this additional smoothing can…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-18 Guillem Domènech , Marc Kamionkowski

We extract the galaxy density and momentum power spectra from a subset of early-type galaxies in the SDSS DR7 main galaxy catalog. Using galaxy distance information inferred from the improved fundamental plane described in…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-03 Stephen Appleby , Motonari Tonegawa , Changbom Park , Sungwook E. Hong , Juhan Kim , Yongmin Yoon

Light scattering is one of the most established wave phenomena in optics, lying at the heart of light-matter interactions and of crucial importance for nanophotonic applications. Passivity, causality and energy conservation imply strict…

Optics · Physics 2022-11-23 Seunghwi Kim , Sergey Lepeshov , Alex Krasnok , Andrea Alù

We present a tentative summary of the many very interesting issues that have been addresses at this workshop, focussing in particular on the perspectives for measuring the polarization power spectra of the Cosmic Microwave Background…

Astrophysics · Physics 2014-10-13 Gianfranco De Zotti , Carlo Burigana , Carlo Baccigalupi

The some models of holographic dark energy for Randall-Sandrum brane are considered. For first class of dark energy models we take energy density in form $\sim L^{2\gamma-4}$ where $L$ is size of events horizon in Universe and $\gamma$ is…

General Relativity and Quantum Cosmology · Physics 2020-03-18 Artyom V. Astashenok , Alexander S. Tepliakov

In a recently proposed model the cosmic rays spectrum at energies above EeV can be fitted with a minimal number of unknown parameters assuming that the extragalactic cosmic rays are only protons with a power law source spectrum. Within this…

Astrophysics · Physics 2007-06-27 O. Kalashev , G. Gelmini , D. Semikoz

We relate the observable number of sources per solid angle and redshift to the underlying proper source density and velocity, background evolution and line-of-sight potentials. We give an exact result in the case of linearized perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-08 Anthony Challinor , Antony Lewis