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We examine cosmic microwave background constraints on variations in the recombination history of the universe. We use a very general extension to the standard model of recombination characterized by two parameters, a and b, which multiply…

Astrophysics · Physics 2007-05-23 Angela M. Linn , Robert J. Scherrer

Forthcoming cosmic microwave background experiments (CMB) will provide precise new tests of structure-formation theories. The geometry of the Universe may be determined robustly, and the classical cosmological parameters, such as the…

Astrophysics · Physics 2007-05-23 Marc Kamionkowski

We study CMB secondary anisotropies produced by inhomogeneous reionization by means of cosmological simulations coupled with the radiative transfer code CRASH. The reionization history is consistent with the WMAP Thomson optical depth…

Astrophysics · Physics 2009-11-10 R. Salvaterra , B. Ciardi , A. Ferrara , C. Baccigalupi

We show that the delay of structure formation from WMAP3 can not fully account for the reduction of electron optical depth from WMAP1 to WMAP3 when the radiative transfer effects and feedback mechanisms are took into account in computing…

Astrophysics · Physics 2007-05-23 L. A. Popa , C. Burigana

The Population III.1 theory for supermassive black hole (SMBH) formation predicts a very early ($z\sim20-25$), transient phase, ``The Flash'', of cosmic reionization powered by supermassive stars that are SMBH progenitors. The universe then…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-23 Jonathan C. Tan , Eiichiro Komatsu

The temperature and polarization of the cosmic microwave background (CMB), as measured today, may offer key insights into the topology of the early universe prior to inflation, for example, by discriminating between flat and warped…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-29 Miguel-Angel Sanchis-Lozano

The recent detection of secondary CMB anisotropy by the South Pole Telescope places a conservative bound on temperature fluctuations from the optical depth-modulated Doppler effect of T_{3000} < sqrt{13} microK at multipoles l~3000. This…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-30 Michael J. Mortonson , Wayne Hu

Massive neutrinos modify the expansion history of the universe and suppress the structure formation below their free streaming scale. Cosmic microwave background (CMB) observations at small angular scales can be used to constrain the total…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-15 Gali Shmueli , Debanjan Sarkar , Ely D. Kovetz

Recent studies by a number of independent collaborations, have correlated the CMB temperatures measured by the WMAP satellite with different galaxy surveys that trace the matter distribution with light from the whole range of the…

Astrophysics · Physics 2009-11-10 E. Gaztanaga , M. Manera , T. Multamaki

Motivated by WMAP's confirmation of an anomalously low value of the quadrupole moment of the CMB temperature fluctuations, we investigate the effects on the CMB of cutting off the primordial power spectrum P(k) at low wave numbers. This…

Astrophysics · Physics 2009-11-07 James M. Cline , Patrick Crotty , Julien Lesgourgues

If a component of cosmological dark matter is made up of massive particles - such as sterile neutrinos - that decay with cosmological lifetime to emit photons, the reionization history of the universe would be affected, and cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 S. Yeung , M. H. Chan , M. -C. Chu

We discuss the possible impact of astrophysical foregrounds on three recent exciting results of Cosmic Microwave Background (CMB) experiments: the WMAP measurements of the temperature-polarization (TE) correlation power spectrum, the…

Astrophysics · Physics 2007-05-23 G. De Zotti , C. Burigana , C. Baccigalupi , R. Ricci

Patchy reionization couples the ionized-bubble morphology to the underlying density field, making the CMB Thomson optical depth sensitive to both the global ionization history and anisotropic fluctuations on the sky. Using the large-volume…

The DASI discovery of CMB polarization, confirmed by WMAP, has opened a new chapter in cosmology. Most of the useful information about inflationary gravitational waves and reionization is on large angular scales where Galactic foreground…

Astrophysics · Physics 2007-05-23 Angelica de Oliveira-Costa

Observations of the polarization of the cosmic microwave backround (CMB) have the potential to place much tighter constraints on cosmological parameters than observations of the fluctuations in temperature alone. We discuss using CMB…

Astrophysics · Physics 2009-10-30 William H. Kinney

We consider a recently proposed scenario for the generation of primordial cosmological perturbations, the so called Cosmological Slingshot scenario. We firstly obtain a general expression for the Slingshot primordial power spectrum which…

Astrophysics · Physics 2009-01-16 Cristiano Germani , Michele Liguori

We study the topology generated by the temperature fluctuations of the Cosmic Microwave Background (CMB) radiation, as quantified by the number of components and holes, formally given by the Betti numbers, in the growing excursion sets. We…

The cosmic microwave background (CMB) is one of the finest probes of cosmology. Its all-sky temperature and linear polarization (LP) fluctuations have been measured precisely at a level of deltaT/TCMB ~10^{-6}. In comparison, circular…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-03 Soma King , Philip Lubin

The large-angular-scale falloff in the autocorrelation function for the cosmic microwave background (CMB) temperature has long intrigued cosmologists and fueled speculation about suppressed superhorizon power. Here we highlight an…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-13 Jahmour J. Givans , Marc Kamionkowski