English
Related papers

Related papers: Cosmic structure sizes in generic dark energy mode…

200 papers

Acceleration of the universe might be driven by a continuous elastic medium -- elastic dark energy (Bucher and Spergel 1999). Elastic dark energy can stably support equations of state with pressure to energy ratio w > -4/3. Stable expansion…

Astrophysics · Physics 2007-05-23 Andrei Gruzinov

It is demonstrated that if cosmic dark energy behaves like a fluid with equation of state $p = {\rm w} \rho (p$ and $\rho$ being pressure and energy density respectively) as well as generalized Chaplygin gas simultaneously, Big Rip or Big…

Astrophysics · Physics 2007-05-23 S. K. Srivastava

One of the principal goals of modern cosmology is to constrain the properties of dark energy. At present, numerous surveys are aiming to determine the equation of state, which is assumed constant due to our poor understanding of its…

Astrophysics · Physics 2009-11-10 Fergus Simpson , Sarah Bridle

We use large-scale cosmological observations to place constraints on the dark-matter pressure, sound speed and viscosity, and infer a limit on the mass of warm-dark-matter particles. Measurements of the cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Martin Kunz , Savvas Nesseris , Ignacy Sawicki

We have found a mechanism which regulates the dark energy in our universe. With an emergent conformal symmetry, the dark energy density is regulated to the order of a conformal anomaly parameter in the conformally coupled gravity. In the…

General Relativity and Quantum Cosmology · Physics 2013-08-30 Yongsung Yoon

In this work, a detailed investigation of compact stars composed of deconfined quark matter with finite strange quark mass ($m_s \neq 0$) admixed with dark energy is presented. The quark sector is modeled using the MIT bag model equation of…

General Relativity and Quantum Cosmology · Physics 2025-11-25 Rohit Roy , Koushik Ballav Goswami , Debadri Bhattacharjee , Pradip Kumar Chattopadhyay

Cosmic structures at large scales represent the earliest and most extended form of matter condensation. In this lecture we review the application of the methods and concepts of modern statistical physics to these structures. This leads to a…

Astrophysics · Physics 2017-08-23 Luciano Pietronero , Francesco Sylos Labini

We perform parametric tests of the consistency of the standard $w$CDM model in the framework of general relativity by carefully separating information between the geometry and growth of structure. We replace each late-universe parameter…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-09 Eduardo J. Ruiz , Dragan Huterer

We assume the cosmological dark sector to consist of pressureless matter and holographic dark energy with a cutoff length proportional to the Ricci scale. The requirement of separate energy-momentum conservation of the components is shown…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Sergio del Campo , Júlio. C. Fabris , Ramón Herrera , Winfried Zimdahl

Rolling tachyon field models are among the candidates suggested as explanations for the recent acceleration of the Universe. In these models the field is expected to interact with gauge fields and lead to variations of the fine-structure…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-28 C. J. A. P. Martins , F. M. O. Moucherek

The amount and nature of dark energy (DE) can be tightly constrained by measuring the spatial correlation features and evolution of a sample of ~ 100,000 galaxy clusters over the redshift range 0<z < 1.5. Such an X-ray survey will discover…

Using the approach of autonomous Hamiltonian dynamical system, we attempt to estimate the as yet unknown upper limit on the size of the galactic halo surrounding galaxies (lenses). The key to determine the size of the halo is to determine…

General Relativity and Quantum Cosmology · Physics 2010-03-02 Amrita Bhattacharya , Ruslan Isaev , K. B. Vijayakumar , Kamal K. Nandi

The cosmic curvature density parameter has been constrained in the present work independent of any background cosmological model. The reconstruction is performed adopting the non-parametric Gaussian Processes (GP). The constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-18 Purba Mukherjee , Narayan Banerjee

Observations have confirmed the accelerated expansion of the universe. The accelerated expansion can be modelled by invoking a cosmological constant or a dynamical model of dark energy. A key difference between these models is that the…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Manvendra Pratap Rajvanshi , Jasjeet Singh Bagla

We analyse the evolution of cosmological perturbations which leads to the formation of large isolated voids in the Universe. We assume that initial perturbations are spherical and all components of the Universe (radiation, matter and dark…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Bohdan Novosyadlyj , Maksym Tsizh , Yurij Kulinich

In this work we consider a flat cosmological model with a set of fluids in the framework of supersymmetric cosmology. The obtained supersymmetric algebra allowed us to take quantum solutions. It is shown that only in the case of a…

General Relativity and Quantum Cosmology · Physics 2010-12-23 J. J. Rosales , V. I. Tkach

We combine cosmic chronometer and growth of structure data to derive the redshift evolution of the dark energy equation of state $w$, using a novel agnostic approach. The background and perturbation equations lead to two expressions for…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-04 Louis Perenon , Matteo Martinelli , Roy Maartens , Stefano Camera , Chris Clarkson

The high-significance measurement of large-scale structure signals enables testing the isotropy of the Universe. The measurement of cosmological parameters through the large-scale distribution of matter is now a mature domain. This approach…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-01 G. Hurier

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 holistic view of the cosmological appearance and development of space is obtained by studying space as a spherically closed surface of a 4-sphere in a zero energy balance between motion and gravitation. Such an approach re-establishes…

Astrophysics · Physics 2009-11-13 Tuomo Suntola