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We examine the constraints that satellite-acquired Type Ia and IIP supernova apparent magnitude versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant…

天体物理学 · 物理学 2009-10-31 Silviu Podariu , Peter Nugent , Bharat Ratra

The kinematic expansion history of the universe is investigated by using the 307 supernovae type Ia from the Union Compilation set. Three simple model parameterizations for the deceleration parameter (constant, linear and abrupt transition)…

宇宙学与河外天体物理 · 物理学 2009-11-13 A. C. C. Guimarães , J. V. Cunha , J. A. S. Lima

We study the angular clustering of Quaia, a Gaia- and unWISE-based catalog of over a million quasars with an exceptionally well-defined selection function. With it, we derive cosmology constraints from the amplitude and growth of structure…

We investigate how the cosmological constraints from SNe Ia are improved by including the effects of weak-lensing convergence. To do so, we introduce the lognormal function as the convergence PDF modeling the lensing scatter of SN Ia…

宇宙学与河外天体物理 · 物理学 2019-06-26 Ryuichiro Hada , Toshifumi Futamase

Despite the broad successes of the flat $\Lambda$CDM model and its fitness to the various cosmological observations, it confronts challenges stemming from anomalies in the measurements of the Hubble constant ($H_0$) and the amplitude of…

宇宙学与河外天体物理 · 物理学 2025-01-28 Saeed Pourojaghi , Mohammad Malekjani

Poincar\`e gauge theory (PGT) is an alternative gravity theory, which attempts to bring the gravity into the gauge-theoretic frame, where the Lagrangian is quadratic in torsion and curvature. Recently, the cosmological models with torsion…

广义相对论与量子宇宙学 · 物理学 2012-03-23 Xi-Chen Ao , Xin-Zhou Li

We present and constrain a cosmological model where the only component is a pressureless fluid with bulk viscosity as an explanation for the present accelerated expansion of the universe. We study the particular model of a bulk viscosity…

广义相对论与量子宇宙学 · 物理学 2009-01-05 Arturo Avelino , Ulises Nucamendi

We present a comprehensive study of galaxy intrinsic alignment (IA) as a probe of parity-violating primordial non-Gaussianity (PNG). Within the effective field theory (EFT) framework, we show that the parity-odd IA power spectrum is…

宇宙学与河外天体物理 · 物理学 2026-04-14 Toshiki Kurita , Drew Jamieson , Eiichiro Komatsu , Fabian Schmidt

We perform unbiased tests for the clumpiness of universe by confronting the Zel'dovich-Kantowski-Dyer-Roeder luminosity distance which describes the effect of local inhomogeneities on the propagation of light with the observational one…

广义相对论与量子宇宙学 · 物理学 2015-04-28 Zhengxiang Li , Xuheng Ding , Zong-Hong Zhu

We consider a very simple toy model for a spatially varying `cosmological constant', where we are inside a spherical bubble (with a given set of cosmological parameters) that is surrounded by a larger region where these parameters are…

天体物理学 · 物理学 2009-11-06 P. P. Avelino , J. P. M. de Carvalho , C. J. A. P. Martins

The search for a physical model which explains the observed recent acceleration of the universe is a compelling task of modern fundamental cosmology. Recently Fernandes \textit{et al.} presented low redshift observational constraints on a…

宇宙学与河外天体物理 · 物理学 2022-02-01 C. J. A. P. Martins , J. S. J. S. Oliveira , D. A. R. Pinheiro

By relaxing the constraint of adiabatic universe used in most cosmological models, we have shown that the new approach provides a better fit to the supernovae Ia redshift data with a single parameter, the Hubble constant $H_0$, than the…

综合物理 · 物理学 2018-10-31 Rajendra P. Gupta

We investigate the observational effects of a quintessence model in an anisotropic spacetime. The anisotropic metric is a non-rotating particular case of a generalized Godel's metric and is classified as Bianchi III. This metric is an exact…

宇宙学与河外天体物理 · 物理学 2014-07-23 W. Miranda , S. Carneiro , C. Pigozzo

We present observations of 10 type Ia supernovae (SNe Ia) between 0.16 < z < 0.62. With previous data from our High-Z Supernova Search Team, this expanded set of 16 high-redshift supernovae and 34 nearby supernovae are used to place…

We perform the first comprehensive constraints on two Finslerian models, i.e., the simplest Finslerian $\Lambda$CDM (F$\Lambda$) and non-flat F$\Lambda$ models using the Type Ia supernovae, baryonic acoustic oscillations, cosmic microwave…

宇宙学与河外天体物理 · 物理学 2021-03-30 Deng Wang , Xin-He Meng

Type Ia Supernovae (SNe Ia) are considered the most reliable \textit{standard candles} and they have played an invaluable role in cosmology since the discovery of the Universe's accelerated expansion. During the last decades, the SNe Ia…

宇宙学与河外天体物理 · 物理学 2024-01-12 Maria Giovanna Dainotti , Giada Bargiacchi , Malgorzata Bogdan , Salvatore Capozziello , Shigehiro Nagataki

Standard cosmology is constructed upon the (generally implicit) assumption of the ``large scale'' homogeneity of our Universe. Now, structures are observed at scales which become larger and larger as the observational distances increase.…

天体物理学 · 物理学 2007-05-23 Marie-Noelle Celerier

We investigate observational constraints on the normal branch of the warped DGP braneworld cosmology by using observational data from Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations (BAO), Cosmic Microwave Background (CMB) and…

宇宙学与河外天体物理 · 物理学 2015-06-03 T. Azizi , M. Sadegh Movahed , Kourosh Nozari

We measure the three-dimensional cross-power spectrum of galaxy density and intrinsic alignment (IA) fields for the first time from the spectroscopic and imaging data of SDSS-III BOSS galaxies, for each of the four samples in the redshift…

宇宙学与河外天体物理 · 物理学 2025-09-09 Toshiki Kurita , Masahiro Takada

Models with a dynamic cosmological term \Lambda (t) are becoming popular as they solve the cosmological constant problem in a natural way. Instead of considering any ad-hoc assumption for the variation of \Lambda, we consider a particular…

广义相对论与量子宇宙学 · 物理学 2015-06-25 R. G. Vishwakarma