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We investigate the degree to which the Cosmic Microwave Background (CMB) can be used to constrain primordial non-Gaussianity coming from the presence of spinning particles coupled to the inflaton. We compute the $\langle TTT \rangle$ and…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-09 Lorenzo Bordin , Giovanni Cabass

We investigate the contribution of cosmic string loops to the Cosmic Microwave Background (CMB) anisotropies. This is done by extending the Unconnected Segment Model (USM) to include the contribution of the cosmic string loops created…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 I. Yu. Rybak , L. Sousa

We present a new analytical method to calculate the small angle CMB temperature angular power spectrum due to cosmic (super-)string segments. In particular, using our method, we clarify the dependence on the intercommuting probability $P$.…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Daisuke Yamauchi , Keitaro Takahashi , Yuuiti Sendouda , Chul-Moon Yoo , Misao Sasaki

We examine the two-point correlation function of local maxima in temperature fluctuations at the last scattering surface when this stochastic field is modified by the additional fluctuations produced by straight cosmic strings via the…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-15 M. Sadegh Movahed , B. Javanmardi , Ravi K. Sheth

Cosmic microwave background (CMB) anisotropy (spatial inhomogeneity) data provide the tightest constraints on the Hubble constant, matter density, spatial curvature, and dark energy dynamics. Other data, sensitive to the evolution of only…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 Chan-Gyung Park , Bharat Ratra

We investigate the observational constraints on the cosmic neutrino background (CNB) given by the extended $\Lambda$CDM scenario ($\Lambda$CDM $+ N_{\rm eff} + \sum m_{\nu} + c^2_{\rm eff} + c^2_{\rm vis} + \xi_{\nu}$) using the latest…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-27 Rafael C. Nunes , Alexander Bonilla

The thin string limit of Cosmic Strings is investigated using a description in terms of Colombeau's theory of nonlinear generalised functions. It is shown that in this description the energy-momentum tensor has a well defined thin string…

General Relativity and Quantum Cosmology · Physics 2007-05-23 K R P Sjodin , J A Vickers

The cosmic microwave background (CMB) has proven to be an invaluable tool for studying the properties and interactions of neutrinos, providing insight not only into the sum of neutrino masses but also the free streaming nature of neutrinos…

High Energy Physics - Phenomenology · Physics 2023-09-07 Stefan Sandner , Miguel Escudero , Samuel J. Witte

Searching for and charactering the non-Gaussianity (NG) of a given field has been a vital task in many fields of science, because we expect the consequences of different physical processes to carry different statistical properties. Here we…

Astrophysics · Physics 2007-05-23 Jiun-Huei Proty Wu

We study the cosmic microwave background temperature and polarisation spectra sourced by multi-tension cosmic superstring networks. First we obtain solutions for the characteristic length scales and velocities associated with the evolution…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Alkistis Pourtsidou , Anastasios Avgoustidis , Edmund J. Copeland , Levon Pogosian , Daniele A. Steer

In the light of the recent results concerning CMB observations and GW detection we address the question of whether it is possible, in a self-consistent inflationary framework, to simultaneously generate a spectrum of scalar metric…

General Relativity and Quantum Cosmology · Physics 2016-12-08 M. Gasperini

In previous work, we constructed a convolutional neural network used to estimate the location of cosmic strings in simulated cosmic microwave background temperature anisotropy maps. We derived a connection between the estimates of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-11 Razvan Ciuca , Oscar F. Hernández

We derive constraints on the time variation of the Higgs vacuum expectation value $<\phi>$ through the effects on Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB). In the former case, we include the…

Astrophysics · Physics 2009-11-07 Jerry Jaiyul Yoo , Robert J. Scherrer

We present constraints on the number of relativistic species from a joint analysis of cosmic microwave background (CMB) fluctuations and light element abundances (helium and deuterium) compared to big bang nucleosynthesis (BBN) predictions.…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-13 Kenneth M. Nollett , Gilbert P. Holder

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)…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-22 Daisuke Yamauchi , Yuuiti Sendouda , Keitaro Takahashi

We compare the anisotropies in the cosmic microwave background radiation measured by the COBE experiment to the predictions of cosmic strings. We use an analytic model for the $\Delta T/T$ power spectrum that is based on our previous…

High Energy Physics - Phenomenology · Physics 2009-10-22 David P. Bennett , Albert Stebbins , Francois R. Bouchet

We constrain the primordial gravitational waves from cosmic microwave background (CMB) and stochastic gravitational wave background (SGWB) observations. SGWB provides the latest way to explore the early universe and the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-25 Jun Li , Guang-Hai Guo

We revise the cosmological bounds on Ho\v{r}ava gravity taking into accounts the stringent constraint on the speed of propagation of gravitational waves from GW170817 and GRB170817A. In light of this we also investigate the degeneracy…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-02 Noemi Frusciante , Micol Benetti

Axion strings are horizon-size topological defects that may be produced in the early Universe. Ultra-light axion-like particles may form strings that persist to temperatures below that of big bang nucleosynthesis. Such strings have been…

High Energy Physics - Phenomenology · Physics 2023-08-04 Joshua N. Benabou , Malte Buschmann , Soubhik Kumar , Yujin Park , Benjamin R. Safdi

We point out that the inclusion of a string component contributing around 5% to the CMB power spectrum amplitude on large scales can increase the preferred value of the spectral index n_s of density fluctuations measured by CMB experiments.…

Astrophysics · Physics 2009-11-11 Richard A. Battye , Bjorn Garbrecht , Adam Moss