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We propose a new model-independent method to test the cosmic curvature by comparing the proper distance and transverse comoving distance. Using the measurements of Hubble parameter $H(z)$ and angular diameter distance $d_A$, the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-11 H. Yu , F. Y. Wang

The most studied way to explain the current accelerated expansion of the universe is to assume the existence of dark energy; a new component that fill the universe, does not clumps, currently dominates the evolution, and has a negative…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Victor H. Cardenas

We constrain two non-flat time-evolving dark energy cosmological models by using Hubble parameter data, Type Ia supernova apparent magnitude measurements, and baryonic acoustic oscillation peak length scale observations. The inclusion of…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Omer Farooq , Data Mania , Bharat Ratra

An approximate statistical description of the formation and evolution of structure of the universe based on the Zel'dovich theory of gravitational instability is proposed. It is found that the evolution of DM structure shows features of…

Astrophysics · Physics 2009-10-31 M. Demianski , A. Doroshkevich

A natural extension of the standard cosmological model are models that include curvature as a free parameter. In this work we study in detail the observational constraints on the non-flat $\Lambda CDM$ model using the two main geometric…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-15 Velasquez-Toribio , A. M , Magnago , A. dos R

We present cosmological dark matter (DM)--only zoom-in simulations of a Milky Way analog originating from enhanced linear matter power spectra $P(k)$ relative to the standard cold, collisionless DM (CDM) cosmology. We consider a Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-23 Ethan O. Nadler , Vera Gluscevic , Andrew Benson

As evidenced by a great number of works, it is common practice to assume that the Universe is flat. However, the majority of studies which make use of observational data to constrain the curvature density parameter are premised on the…

General Relativity and Quantum Cosmology · Physics 2019-07-18 Christine R. Farrugia , Joseph Sultana

The cosmic curvature $\Omega_{K,0}$, which determines the spatial geometry of the universe, is an important parameter in modern cosmology. Any deviation from $\Omega_{K,0}=0$ would have a profound impact on primordial inflation paradigm and…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-14 Peng-Ju Wu , Jing-Zhao Qi , Xin Zhang

We use two subsets of 2000 and 1000 Quijote simulations to build two power spectrum emulators, allowing for fast computations of the non-linear matter power spectrum. The first emulator is built in terms of seven cosmological parameters:…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-09 Andrei Lazanu

In the $\Lambda$CDM model, cosmological observations from the late and recent universe reveal a puzzling $\sim 4.5\sigma$ tension in the current rate of universe expansion. In addition to the various scenarios suggested to resolve the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Maryam Vazirnia , Ahmad Mehrabi

In the present work, we study the noncommutative version of a quantum cosmology model. The model has a Friedmann-Robertson-Walker geometry, the matter content is a radiative perfect fluid and the spatial sections have zero constant…

General Relativity and Quantum Cosmology · Physics 2016-05-05 G. Oliveira-Neto , M. Silva de Oliveira , G. A. Monerat , E. V. Corrêa Silva

The vacuum inflation with a boundary condition specified at a short-distance scale in a generally primeval non-flat Universe, and implications of the correspondingly modified primordial power spectrum via the WMAP data are investigated. We…

Astrophysics · Physics 2009-09-28 Jie Ren , Hong-Guang Zhang , Xin-He Meng

We consider gravity mediated by non-metricity, with vanishing curvature and torsion. The gravitational action, including an arbitrary function of the non-metric scalar, is investigated in view of characterizing the dark energy effects. In…

General Relativity and Quantum Cosmology · Physics 2022-07-13 Salvatore Capozziello , Rocco D'Agostino

Structure formation at small cosmological scales provides an important frontier for dark matter (DM) research. Scenarios with small DM particle masses, large momenta or hidden interactions tend to suppress the gravitational clustering at…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-27 Riccardo Murgia , Alexander Merle , Matteo Viel , Maximilian Totzauer , Aurel Schneider

The cosmographic approach is adopted to determine the spatial curvature (i.e., $\Omega_K$) combining the latest released cosmic chronometers data (CC), the Pantheon sample of type Ia supernovae observations, and the baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 En-Kun Li , Minghui Du , Lixin Xu

We present numerical measurements of the power spectrum response function of the gravitational growth of cosmic structures, defined as the functional derivative of the nonlinear spectrum with respect to the linear counterpart, based on…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-20 Takahiro Nishimichi , Francis Bernardeau , Atsushi Taruya

In the present investigation we use observational data of $ f \sigma_ {8} $ to determine observational constraints in the plane $(\Omega_{m0},\sigma_{8})$ using two different methods: the growth factor parametrization and the numerical…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 A. M. Velásquez-Toribio , Júlio C. Fabris

Constraints on gravity and cosmology will greatly benefit from performing joint clustering and weak lensing analyses on large-scale structure data sets. Utilising non-linear information coming from small physical scales can greatly enhance…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-17 Benjamin Bose , Hans A. Winther , Alkistis Pourtsidou , Santiago Casas , Lucas Lombriser , Qianli Xia , Matteo Cataneo

We present a method for calculating large numbers of power spectra C_l and P(k) that accelerates CMBfast by a factor around 10^3 without appreciable loss of accuracy, then apply it to constrain 11 cosmological parameters from current Cosmic…

Astrophysics · Physics 2009-10-07 Max Tegmark , Matias Zaldarriaga , Andrew J. S. Hamilton

We derive a non-perturbative, closed, analytic equation for the non-linear power spectrum of cosmic density fluctuations. This result is based on our kinetic field theory (KFT) of cosmic structure formation and on evaluating particle…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-23 Matthias Bartelmann , Felix Fabis , Sara Konrad , Elena Kozlikin , Robert Lilow , Carsten Littek , Johannes Dombrowski
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