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We investigate the effect of the stochastic gravitational wave (GW) background produced by kinks on infinite cosmic strings, whose spectrum was derived in our previous work, on the B-mode power spectrum of the cosmic microwave background…

宇宙学与河外天体物理 · 物理学 2010-11-11 Masahiro Kawasaki , Koichi Miyamoto , Kazunori Nakayama

We present constraints on a cosmic string network with a measurement of weak gravitational lensing from CMB temperature map. The cosmic string network between observer and last scattering surface of CMB photons generates vector and/or…

宇宙学与河外天体物理 · 物理学 2015-06-17 Toshiya Namikawa , Daisuke Yamauchi , Atsushi Taruya

We use wavelet and curvelet transforms to extract signals of cosmic strings from cosmic microwave background (CMB) temperature anisotropy maps, and to study the limits on the cosmic string tension which various ongoing CMB temperature…

宇宙学与河外天体物理 · 物理学 2017-06-21 Lukas Hergt , Adam Amara , Robert Brandenberger , Tomasz Kacprzak , Alexandre Refregier

Cosmic string networks generate cosmological perturbations actively throughout the history of the universe. Thus, the string sourced anisotropy of the cosmic microwave background is not affected by Silk damping as much as the anisotropy…

天体物理学 · 物理学 2010-04-15 Levon Pogosian , S. -H. Henry Tye , Ira Wasserman , Mark Wyman

We find the constraints from WMAP and SDSS data on the fraction of cosmological fluctuations sourced by local cosmic strings using a Markov Chain Monte Carlo (MCMC) analysis. In addition to varying the usual 6 cosmological parameters and…

天体物理学 · 物理学 2014-10-13 Mark Wyman , Levon Pogosian , Ira Wasserman

Scaling networks of cosmic defects, such as strings and textures, actively generate scalar, vector and tensor metric perturbations throughout the history of the universe. In particular, {\em vector} modes sourced by defects are an efficient…

宇宙学与河外天体物理 · 物理学 2014-05-09 Adam Moss , Levon Pogosian

We investigate cosmological evolution and implications of cosmic strings with time-dependent tension. We derive basic equations of time development of the correlation length and the velocity of such strings, based on the one scale model.…

高能物理 - 唯象学 · 物理学 2008-11-26 Kazuhide Ichikawa , Tomo Takahashi , Masahide Yamaguchi

We study the effect of weak lensing by cosmic (super-)strings on the anisotropies of cosmic microwave background (CMB). In developing a method to calculate the lensing convergence field due to strings, and thereby temperature and…

宇宙学与河外天体物理 · 物理学 2015-03-19 Daisuke Yamauchi , Keitaro Takahashi , Yuuiti Sendouda , Chul-Moon Yoo

We present a significant improvement over our previous calculations of the cosmic string contribution to cosmic microwave background (CMB) power spectra, with particular focus on sub-WMAP angular scales. These smaller scales are relevant…

宇宙学与河外天体物理 · 物理学 2015-03-17 Neil Bevis , Mark Hindmarsh , Martin Kunz , Jon Urrestilla

Cosmic strings are a well-motivated extension to the standard cosmological model and could induce a subdominant component in the anisotropies of the cosmic microwave background (CMB), in addition to the standard inflationary component. The…

天体物理仪器与方法 · 物理学 2017-09-18 J. D. McEwen , S. M. Feeney , H. V. Peiris , Y. Wiaux , C. Ringeval , F. R. Bouchet

In this work we study the imprints of a primordial cosmic string on inflationary power spectrum. Cosmic string induces two distinct contributions on curvature perturbations power spectrum. The first type of correction respects the…

宇宙学与河外天体物理 · 物理学 2017-07-19 Sadra Jazayeri , Alireza Vafaei Sadr , Hassan Firouzjahi

We study the impact of kinks on the cosmic microwave background (CMB) anisotropies generated by cosmic string networks. To do so, we extend the Unconnected Segment Model to describe the stress-energy tensor of a network of cosmic strings…

宇宙学与河外天体物理 · 物理学 2023-08-02 Rodrigo P. Silva , Lara Sousa , Ivan Yu. Rybak

We calculate the cosmic microwave background (CMB) $B$-mode power spectrum resulting from anisotropic cosmic birefringence, without relying on the thin approximation of the last scattering surface. Specifically, we consider the influence of…

宇宙学与河外天体物理 · 物理学 2025-03-04 Toshiya Namikawa

We present a new probe of purely gravitationally coupled sectors with large anisotropies. These anisotropies are damped via gravitational interactions with the baryon-photon fluid, which is heated up in the process. The injected heat causes…

高能物理 - 唯象学 · 物理学 2023-02-16 Nicklas Ramberg , Wolfram Ratzinger , Pedro Schwaller

We explore the use of random forest and gradient boosting, two powerful tree-based machine learning algorithms, for the detection of cosmic strings in maps of the cosmic microwave background (CMB), through their unique Gott-Kaiser-Stebbins…

宇宙学与河外天体物理 · 物理学 2018-10-12 A. Vafaei Sadr , M. Farhang , S. M. S. Movahed , B. Bassett , M. Kunz

By considering simple, but representative, models of brane inflation from a single brane-antibrane pair in the slow roll regime, we provide constraints on the parameters of the theory imposed by measurements of the CMB anisotropies by WMAP…

天体物理学 · 物理学 2008-11-26 Richard A. Battye , Bjorn Garbrecht , Adam Moss , Horace Stoica

In our previous work, we found new types of the cosmic string solutions in the Abelian-Higgs model with an enhanced $U(1)$ global symmetry. We dubbed those solutions as the compensated/uncompensated strings. The compensated string is…

高能物理 - 唯象学 · 物理学 2020-09-08 Takashi Hiramatsu , Masahiro Ibe , Motoo Suzuki

We study the effect of weak lensing by cosmic (super-)strings on the higher-order statistics of the cosmic microwave background (CMB). A cosmic string segment is expected to cause weak lensing as well as an integrated Sachs-Wolfe (ISW)…

宇宙学与河外天体物理 · 物理学 2014-10-22 Daisuke Yamauchi , Yuuiti Sendouda , Keitaro Takahashi

We study future observational constraints on cosmic string parameters from various types of next-generation experiments: direct detection of gravitational waves (GWs), pulsar timing array, and the cosmic microwave background (CMB). We…

宇宙学与河外天体物理 · 物理学 2013-05-30 Sachiko Kuroyanagi , Koichi Miyamoto , Toyokazu Sekiguchi , Keitaro Takahashi , Joseph Silk

We use the publicly available code CMBFAST as modified by L. Pogosian and T. Vachaspati to simulate the effects of wiggly cosmic strings on the Cosmic Microwave Background (CMB). Using the modified CMBFAST code which takes into account…

天体物理学 · 物理学 2011-05-10 N. Simatos , L. Perivolaropoulos