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Related papers: Betti Functionals as a Probe for Cosmic Topology

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I present recent work aimed at showing how currently competing theories of the early universe leave their imprint on the temperature anisotropies of the CMB radiation. We consider the 3-point correlation function, as well as the inherent…

Astrophysics · Physics 2007-05-23 Alejandro Gangui

We propose an alternative formalism to simulate CMB temperature maps in $\Lambda$CDM universes with nontrivial spatial topologies. This formalism avoids the need to explicitly compute the eigenmodes of the Laplacian operator in the spatial…

Astrophysics · Physics 2008-11-26 W. S. Hipolito-Ricaldi , G. I. Gomero

The cosmic curvature $\Omega_{K}$ is an important parameter related to the inflationary cosmology and the ultimate fate of the universe. In this work, we adopt the non-CMB observations to constrain $\Omega_{K}$ in the $\Lambda$CDM model and…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-12 Peng-Ju Wu , Xin Zhang

We present a sample-variance-limited measurement of the temperature power spectrum ($TT$) of the cosmic microwave background (CMB) using observations of a $\sim\! 1500 \,\mathrm{deg}^2$ field made by SPT-3G in 2018. We report multifrequency…

The question of whether Cosmic Microwave Background (CMB) temperature and polarization data from Planck favor a spatially closed Universe with curvature parameter $\Omega_K<0$ has been the subject of recent intense discussions. Attempts to…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-18 Sunny Vagnozzi , Abraham Loeb , Michele Moresco

The standard model of cosmology, {\Lambda}CDM, is the simplest model that matches the current observations, but it relies on two hypothetical components, to wit, dark matter and dark energy. Future galaxy surveys and cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-13 Cyrille Doux , Mariana Penna-Lima , Sandro D. P. Vitenti , Julien Tréguer , Eric Aubourg , Ken Ganga

Boyle and Turok's $CPT$-symmetric universe model posits that the universe was symmetric at the Big Bang, addressing numerous problems in both cosmology and the Standard Model of particle physics. We extend this model by incorporating the…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-14 Wei-Ning Deng , Will Handley

We consider a Universe with a three-torus topology which before inflation is devoid of any matter or radiation. Its pre-inflationary evolution is driven solely by Casimir energies of the existing fields, with a radiation-like equation of…

High Energy Physics - Theory · Physics 2026-03-27 Bartosz Fornal

In this paper I will first outline an effective field theory for cosmology (EFTC) that is based on the Standard Model coupled to General Relativity and improved with Weyl symmetry. There are no new physical degrees of freedom in this…

General Relativity and Quantum Cosmology · Physics 2018-11-21 Itzhak Bars

We consider cosmic chronometer (CC) data for the Hubble parameter, quasar (QSO) luminosities data of X-rays and ultraviolet rays emission, and the latest measurements of the present value of the Hubble parameter from 2018 Planck mission…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 Bikash R. Dinda , Haveesh Singirikonda , Subhabrata Majumdar

The effect of a non-trivial topology on the temperature correlations on the cosmic microwave background (CMB) in a small compact hyperbolic universe with volume comparable to the cube of the curvature radius is investigated. Because the…

Astrophysics · Physics 2014-10-13 Kaiki Taro Inoue , Kenji Tomita , Naoshi Sugiyama

Recent observational results suggest that our universe is nearly flat and well modelled within a $\Lambda$CDM framework. The observed values of $\Omega_{m}$ and $\Omega_{\Lambda}$ inevitably involve uncertainties. Motivated by this, we make…

General Relativity and Quantum Cosmology · Physics 2009-11-10 B. Mota , M. J. Reboucas , R. Tavakol

The periodic solution of the Friedmann equation in conformal time, implies that only cosmological perturbations exhibiting corresponding symmetries are physically permissible, leading to a discrete spectrum of allowed wave vectors.…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-15 Wei-Ning Deng , Will Handley

If the assumption that physical space has a trivial topology is dropped, then the Universe may be described by a multiply connected Friedmann-Lema\^{\i}tre model on a sub-horizon scale. Specific candidates for the multiply connected space…

Astrophysics · Physics 2011-05-23 Boudewijn F. Roukema , Jean-Pierre Luminet

The recent Planck Legacy 2018 release has confirmed the presence of an enhanced lensing amplitude in CMB power spectra compared to that predicted in the standard $\Lambda$CDM model. A closed universe can provide a physical explanation for…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-07 Eleonora Di Valentino , Alessandro Melchiorri , Joseph Silk

We present an update to the search for a non-trivial topology of the universe by searching for matching circle pairs in the cosmic microwave background using the WMAP 7 year data release. We extend the exisiting bounds to encompass a wider…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Pascal M. Vaudrevange , Glenn D. Starkman , Neil J. Cornish , David N. Spergel

In the context of the gravity-thermodynamics conjecture based on the Tsallis entropy-area relation, we investigate the standard $\Lambda$CDM cosmology and examine some potential deviations from it. Utilizing recent updates from geometrical…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-25 N. Shahhoseini , M. Malekjani , A. Khodam-Mohammadi

We study dynamics of $\Lambda(t)$ cosmological models which are a natural generalization of the standard cosmological model (the $\Lambda$CDM model). We consider a class of models: the ones with a prescribed form of…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-29 Marek Szydlowski , Aleksander Stachowski

Using the gauge/gravity correspondence, we study the properties of 2-point correlation functions of finite-temperature strongly coupled gauge field theories, defined on a curved space of general spatial topology with a dual black hole…

High Energy Physics - Theory · Physics 2015-06-05 Igal Arav , Yaron Oz

This paper continues the building of the cosmological theory that was introduced in two earlier papers under the title A Dust Universe Solution to the Dark Energy Problem. The model introduced in this theory has existence before time zero…

General Physics · Physics 2010-02-21 James G. Gilson