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We study the power spectrum of the mass density perturbations in an inflation scenario that includes thermal dissipation. We show that the condition on which the thermal fluctuations dominate the primordial density perturbations can easily…

Astrophysics · Physics 2009-10-31 Wolung Lee , Li-Zhi Fang

In the expanding Universe, the average temperature of the cosmic microwave background (CMB) is expected to depend like TCMB~(1+z) on redshift z. Adiabatic photon production (or destruction) or deviations from isotropy and homogeneity could…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Jens Chluba

We introduce a simple yet powerful {\it analytic} method which obtains the structure of cosmic microwave background anisotropies to better than 5-10\% in temperature fluctuations on {\it all} scales. It is applicable to {\it any} model in…

Astrophysics · Physics 2009-07-17 Wayne Hu , Naoshi Sugiyama

%The content of this replacement paper is identical to the original. %We have attempted to fix the postscript so that it will print out on %a larger number of printers. Using recent experimental limits on $\mu$ distortions from COBE FIRAS,…

Astrophysics · Physics 2009-10-22 Wayne Hu , Douglas Scott , Joseph Silk

Inflationary predictions based on the linear theory of cosmological perturbations are related to the two point function of a (second quantized) real scalar free field during the accelerated stage. Such a two point function is finite, in…

High Energy Physics - Theory · Physics 2008-11-26 F. Finelli , G. Marozzi , G. P. Vacca , G. Venturi

The redshift dependence of the cosmic microwave background temperature, $T(z)=T_0(1+z)$, is a key prediction of standard cosmology, but this relation is violated in many extensions thereof. Current astrophysical facilities can probe it in…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-09 C. J. A. P. Martins , A. M. M. Vieira

When using an electron microscope for imaging of particles embedded in vitreous ice, the objective lens will inevitably corrupt the projection images. This corruption manifests as a band-pass filter on the micrograph. In addition, it causes…

Image and Video Processing · Electrical Eng. & Systems 2020-01-29 Ayelet Heimowitz , Joakim Andén , Amit Singer

As a test of the standard inflationary cosmology, which generically predicts nearly scale-invariant spectrum of primordial curvature fluctuations, we perform Markov-Chain Monte-Carlo analysis to search for possible modulations in the power…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-12 Kiyotomo Ichiki , Ryo Nagata , Jun'ichi Yokoyama

We introduce a new distortion measure for point processes called functional-covering distortion. It is inspired by intensity theory and is related to both the covering of point processes and logarithmic loss distortion. We obtain the…

Information Theory · Computer Science 2022-04-21 Nirmal V. Shende , Aaron B. Wagner

We solve the recombination equation by taking into account the induced recombinations and a physical cut off in the hydrogen spectrum. The effective recombination coefficient is parametrized as a function of temperature and free electron…

Astrophysics · Physics 2008-02-03 Peter Boschan , Peter Biltzinger

In this article, we describe and validate the first fully automatic parameter optimization for thermal synthetic aperture visualization. It replaces previous manual exploration of the parameter space, which is time consuming and error…

Computer Vision and Pattern Recognition · Computer Science 2020-05-11 Indrajit Kurmi , David C. Schedl , Oliver Bimber

The probability density function of accretion disc luminosity fluctuations at high observed energies (i.e., energies larger than the peak temperature scale of the disc) is derived, under the assumption that the temperature fluctuations are…

High Energy Astrophysical Phenomena · Physics 2022-10-12 Andrew Mummery , Steven Balbus

Cross-correlations between Cosmic Microwave Background (CMB) temperature and $y$-spectral distortions anisotropies have been previously proposed as a way to measure the local bispectrum parameter $f_{\rm NL}^{\rm loc.}$ in a range of scales…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-04 Andrea Ravenni , Michele Liguori , Nicola Bartolo , Maresuke Shiraishi

The modeling of stellar spectra is pervasive in astronomy. Conventionally, the shapes of absorption lines are modeled by convolving thermal profiles (computed given some model stellar atmosphere and line list) with broadening kernels…

Solar and Stellar Astrophysics · Physics 2025-12-11 Michael L. Palumbo

Diffusion tensor coefficients play a central role in describing cosmic-ray transport in various astrophysical environments permeated with magnetic fields, which are usually modeled as a fluctuating field on top of a mean field. In this…

High Energy Astrophysical Phenomena · Physics 2024-07-09 O. Deligny

Spectral distortion anisotropies of the cosmic microwave background (CMB) provide a new probe of the early Universe that can be accessed using traditional CMB imaging techniques. It is possible to compute the creation and evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-17 Jens Chluba , Sara Evangelista , Tom Daman , Geoff Vasil

The angular power spectrum of the cosmic microwave background temperature anisotropy observed by WMAP has an anomalous dip at l~20 and bump at l~40. One explanation for this structure is the presence of features in the primordial curvature…

Cosmology and Nongalactic Astrophysics · Physics 2009-05-19 Michael J. Mortonson , Cora Dvorkin , Hiranya V. Peiris , Wayne Hu

Density functional perturbation theory is a well-established method to study responses of molecules and solids, especially responses to atomic displacements or to different perturbing fields (electric, magnetic). Like for density functional…

Materials Science · Physics 2024-02-16 Xavier Gonze , Samare Rostami , Christian Tantardini

We study the effect of mesoscopic fluctuations on a magnetic impurity coupled to a spatially confined electron gas with a temperature in the mesoscopic range (i.e. between the mean level spacing $\Delta$ and the Thouless energy $E_{\rm…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Ribhu K. Kaul , Denis Ullmo , Shailesh Chandrasekharan , Harold U. Baranger

Mixing of blackbodies with different temperatures creates a spectral distortion which, at lowest order, is a y-type distortion, indistinguishable from the thermal y-type distortion produced by the scattering of CMB photons by hot electrons…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-11 Rishi Khatri , Rashid A. Sunyaev , Jens Chluba
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