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Related papers: Can we avoid dark energy?

200 papers

The standard cosmological model is in the midst of a stress test, thanks to the tension between supernovae-based measurements of the Hubble constant $H_{0}$ and inferences of its values from Cosmic Microwave Background (CMB) anisotropies.…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-05 K. Rezazadeh , A. Ashoorioon , D. Grin

We use Hubble parameter versus redshift data from Stern, et al(2010) and Gazta\~{n}aga, et al (2009) to place constraints on model parameters of constant and time-evolving dark energy cosmological models. These constraints are consistent…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-12 Yun Chen , Bharat Ratra

The latest cosmological constraints on the sum of the neutrino masses depend on prior physical assumptions about the mass spectrum. To test the accordance of cosmological and laboratory constraints in the absence of such priors, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-14 Willem Elbers , Carlos S. Frenk , Adrian Jenkins , Baojiu Li , Silvia Pascoli

We show that the redshift-space quadrupole will be a powerful tool for constraining dark energy even if the baryon oscillations are missing from the usual monopole power spectrum and even if bias is scale- and time-dependent. We calculate…

Astrophysics · Physics 2009-11-10 Kazuhiro Yamamoto , Bruce A. Bassett , Hiroaki Nishioka

Explanations of the late-time cosmic acceleration within the framework of general relativity are plagued by difficulties. General relativistic models are mostly based on a dark energy field with fine-tuned, unnatural properties. There is a…

Astrophysics · Physics 2010-04-22 Ruth Durrer , Roy Maartens

Baryon acoustic oscillation (BAO) is one of the important standard rulers in cosmology. The results of the latest BAO measurements by Dark Energy Spectroscopic Instrument (DESI) survey have been reported. Cosmology with the varying electron…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-23 Osamu Seto , Yo Toda

We introduce a new parametrization for the dark energy, led by the same idea to the linear expansion of the equation of state in scale factor $a$ and in redshift $z$, which diverges neither in the past nor future and contains the same…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Ozgur Akarsu , Tekin Dereli , J. Alberto Vazquez

We examine the decay vacuum model with a parameter $\epsilon$ that indicates the vacuum energy decay rate. By constraining this model with cosmic microwave background radiation, baryon acoustic oscillation, type Ia supernovae and 30 H(z)…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-04 Yang-Jie Yan , Deng Wang , Xin-He Meng

We note that the standard LCDM cosmological model continues to face fundamental problems. First, the model continues to depend wholly on two pieces of undiscovered physics, namely dark energy and cold dark matter. Then, the implied dark…

Astrophysics · Physics 2019-10-23 T. Shanks

We use a spherical model and an extended excursion set formalism with drifting diffusive barriers to predict the abundance of cosmic voids in the context of general relativity as well as f(R) and symmetron models of modified gravity. We…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-15 Rodrigo Voivodic , Marcos Lima , Claudio Llinares , David F. Mota

We investigate the possibility of a dark energy component that is scaling with epochs. A phenomenological model is introduced whose energy density depends on the redshift in such a way that a smooth transition among the three dominant…

Astrophysics · Physics 2009-11-10 Salvatore Capozziello , Alessandro Melchiorri , Alice Schirone

We compare supernovae and Baryon Acoustic Oscillations data to the predictions of a cosmological model of interacting dark matter and dark energy. This theoretical model can be derived from the effective field theory of Einstein-Cartan…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 Damien Bégué , Clément Stahl , She-Sheng Xue

We study the growth of matter perturbations beyond the linear level in cosmologies in which the dark energy has a variable equation of state. The non-linear corrections result in shifts in the positions of the maximum, minima and nodes of…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-11 N. Brouzakis , N. Tetradis

This short review was prepared as an introduction to the Royal Society's 'Dark Matter' conference. It addresses the embarrassing fact that 95% of the universe is unaccounted for. Favoured dark matter candidates are axions or…

Astrophysics · Physics 2010-12-09 Martin J. Rees

A cosmological model is proposed for the current Universe consisted of non-interacting baryonic matter and interacting dark components. The dark energy and dark matter are coupled through their effective barotropic indexes, which are…

Astrophysics · Physics 2009-06-15 Luis P. Chimento , Monica Forte , Gilberto M. Kremer

We discuss models that can account for today's dark energy. The underlying cosmological constant may be Planck scale but starts as a redundant coupling which can be eliminated by a field redefinition. The observed vacuum energy arises when…

High Energy Physics - Theory · Physics 2008-11-26 Puneet Batra , Kurt Hinterbichler , Lam Hui , Daniel Kabat

Sharp features in the primordial power spectrum are a powerful window into the inflationary epoch. To date, the cosmic microwave background (CMB) has offered the most sensitive avenue to search for these signatures. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 Florian Beutler , Matteo Biagetti , Daniel Green , Anže Slosar , Benjamin Wallisch

The high-quality cosmological data, which became available in the last decade, have thrusted upon us a rather preposterous composition for the universe which poses one of the greatest challenges theoretical physics has ever faced: the…

Astrophysics · Physics 2015-06-24 J. S. Alcaniz

We study a power-law $F(R)$ gravity with an early dark energy term, that can describe both the early-time and the late-time acceleration of the Universe. We confront this scenario with recent observational data including the Pantheon Type…

General Relativity and Quantum Cosmology · Physics 2023-06-28 Sergei D. Odintsov , V. K. Oikonomou , German S. Sharov

We show that mass varying neutrinos (MaVaNs) can behave as a negative pressure fluid which could be the origin of the cosmic acceleration. We derive a model independent relation between the neutrino mass and the equation of state parameter…

Astrophysics · Physics 2009-11-10 Rob Fardon , Ann E. Nelson , Neal Weiner