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Related papers: Cosmic Strings and Cosmic Variance

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We computed the power spectrum of weak cosmic shear in models with non-Gaussian primordial density fluctuations. Cosmological initial conditions deviating from Gaussianity have recently attracted much attention in the literature, especially…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 C. Fedeli , L. Moscardini

Using the three-component spectral model describing the FIRAS average continuum spectra, the analytical expressions for the temperature dependence of the thermodynamic and radiative functions of the galactic far-infrared radiation are…

Astrophysics of Galaxies · Physics 2015-06-19 Anatoliy I Fisenko , Vladimir Lemberg

Cosmic strings, theoretical one-dimensional topological defects from the early universe, provide a valuable opportunity for exploring dark matter (DM) production and gravitational wave (GW) emission. Our study investigates the production of…

High Energy Physics - Phenomenology · Physics 2024-09-25 Hanyu Cheng , Luca Visinelli

Pulsar timing arrays are one of the powerful tools to test the existence of cosmic strings through searching for the gravitational wave background. The amplitude of the background connects to information on cosmic strings such as the…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-03 Sachiko Kuroyanagi , Keitaro Takahashi , Naoyuki Yonemaru , Hiroki Kumamoto

We compute the power spectra in the cosmic microwave background and cold dark matter (CDM) fluctuations seeded by strings, using the largest string simulations performed so far to evaluate the two-point functions of their stress energy…

Astrophysics · Physics 2009-10-30 Carlo Contaldi , Mark Hindmarsh , Joao Magueijo

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…

Instrumentation and Methods for Astrophysics · Physics 2017-09-18 J. D. McEwen , S. M. Feeney , H. V. Peiris , Y. Wiaux , C. Ringeval , F. R. Bouchet

Observational cosmology is entering an era in which high precision will be required in both measurement and data analysis. Accuracy, however, can only be achieved with a thorough understanding of potential sources of contamination from…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-19 Assaf Ben-David , Sebastian von Hausegger , Andrew D. Jackson

String models can produce successful inflationary scenarios in the context of brane collisions and in many of these models cosmic strings may also be produced. In scenarios such as KKLMMT the string contribution is naturally predicted to be…

Astrophysics · Physics 2009-11-11 Uros Seljak , Anze Slosar

We investigate the emission of vector radiation by superconducting cosmic string loops, deriving general relations to characterize the vector radiation emission efficiency, and study its impact on the evolution of loops. Building on these…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-27 I. Yu. Rybak , L. Sousa

We calculate the gravitational radiation emitted by an infinite cosmic string with two oppositely moving wave-trains, in the small amplitude approximation. After comparing our result to the previously studied cases we extend the results to…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Xavier Siemens , Ken D. Olum

A full quantum description of global vortex strings is presented in the framework of a pure Higgs system with a broken global U(1) symmetry in 3+1D. An explicit expression for the string creation operator is obtained, both in terms of the…

High Energy Physics - Theory · Physics 2009-10-31 H. Fort , E. Marino

We simulate the formation of cosmic strings at the zeros of a complex Gaussian field with a power spectrum $P(k) \propto k^n$, specifically addressing the issue of the fraction of length in infinite strings. We make two improvements over…

High Energy Physics - Phenomenology · Physics 2009-10-30 Robert J. Scherrer , Alexander Vilenkin

The production of a primordial stochastic gravitational-wave background by processes occuring in the early Universe is expected in a broad range of models. Observing this background would open a unique window onto the Universe's…

Cosmic strings are one-dimensional topological defects which could have been formed in the early stages of our Universe. They triggered a lot of interest, mainly for their cosmological implications: they could offer an alternative to…

High Energy Physics - Theory · Physics 2009-11-11 Mairi Sakellariadou

In this work we present a partially new method to analyze fluctuations which are induced by causal scaling seeds. We show that the power spectra due to this kind of seed perturbations are determined by five analytic functions, which we…

Astrophysics · Physics 2008-11-26 Ruth Durrer , Martin Kunz

I report recent studies on the evolution of perturbations in the context of the ``pre-big-bang" scenario typical of string cosmology, with emphasis on the formation of a stochastic background of relic photons and gravitons, and its possible…

High Energy Physics - Theory · Physics 2009-09-25 M. Gasperini

The angular two-point correlation function between background QSOs and foreground galaxies induced by gravitational lensing is derived. It is shown that the shape of this correlation function depends sensitively on the spectrum of the…

Astrophysics · Physics 2007-05-23 Matthias Bartelmann

The cosmic string is a useful probe of the early Universe and may give us a clue to physics at high energy scales where any artificial particle accelerators cannot reach. Although one of the most promising tools is the cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Kohei Kamada , Yuhei Miyamoto , Jun'ichi Yokoyama

Photons can gravitationally scatter off a cosmic string loop and gain or lose energy. We consider the spectral distortion induced by cosmic string loops placed in an ambient thermal bath of photons. The fractional deviation from a thermal…

High Energy Physics - Theory · Physics 2013-04-17 Yi-Zen Chu , Tanmay Vachaspati

The nonlinear parameter measures the amplitude of primordial non-Gaussianity in the cosmic microwave background radiation (CMB), offering a crucial test of early universe models. While standard single field inflation predicts nearly…

Statistics Theory · Mathematics 2025-07-11 Claudio Durastanti