相关论文: Limits of Quasi-Static Approximation in Modified-G…

A stochastic background of gravitational waves is expected to arise from a superposition of a large number of unresolved gravitational-wave sources of astrophysical and cosmological origin. It is expected to carry unique signatures from the…

We investigate a quasi-local energy naturally introduced by Kodama's prescription for a spherically symmetric space-time with a positive cosmological constant $\Lambda$. We find that this quasi-local energy is well behaved inside a…

We constrain cold dark energy of negligible sound speed using galaxy cluster abundance observations. In contrast to standard quasi-homogeneous dark energy, negligible sound speed implies clustering of the dark energy fluid at all scales,…

It is shown that varying speed of light cosmology follows from a string-inspired minimal length uncertainty relation. Due to the reduction of the available phase space volume per quantum mode at short wavelengths, the equation of state of…

Hod's proposal claims that the least damped quasinormal mode of a black hole must have the imaginary part smaller than half of the surface gravity at the event horizon. The Strong Cosmic Censorship in General Relativity implies that this…

A quasi-static approximation (QSA) for modified gravity can be applied in a number of ways. We consider three different analytical formulations based on applying this approximation to: (1) the field equations; (2) the equations for the two…

We present a model-independent null test of the late-time cosmological response to a reduced sound horizon, as typically required by early-universe solutions to the Hubble tension. In this approach, we phenomenologically impose a shorter…

In a companion paper (hep-th/0609150), we have introduced a model of scalar field dark energy, Cuscuton, which can be realized as the incompressible (or infinite speed of sound) limit of a k-essence fluid. In this paper, we study how…

The original theory of quasi-metric gravity, admitting only a partial coupling between space-time geometry and the active stress-energy tensor, is too restricted to allow the existence of gravitational waves in vacuum. Therefore, said…

In the present paper, we investigate the quasinormal modes of an Einstein-Maxwell power-Yang-Mills black hole in four dimensions, considering a specific value of the power parameter $p = 1/2$. This particular case represents a black hole…

We review the implications of having a non-trivial matter component in the universe and the potential for detecting such a component through the matter power spectrum and ISW effect. We adopt a phenomenological approach and consider the…

We investigate the potential of the Square Kilometer Array Telescope (SKA) to constrain the sound speed of dark energy. The Integrated Sachs Wolfe (ISW) effect results in a significant power spectrum signal when CMB temperature anisotropies…

Quantum speed limit (QSL) under noise has drawn considerable attention in real quantum computational processes and quantum communication. Though non-Markovian noise is proven to be able to accelerate quantum evolution for a damped…

We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…

The quasilocalized charge approximation is applied to estimate the sound velocity of simple soft sphere fluid with the repulsive inverse-power-law interaction. The obtained results are discussed in the context of the sound velocity of the…

In this paper we present a generic form of the cosmological Equation of State derived from the formalism of Statistical Mechanics, assuming that a cosmic acceleration scenario can be interpreted as a system of quasi-particles. By…

In this paper we discuss the commonly-used limiting cases, or approximations, for two-point cosmic shear statistics. We discuss the most prominent assumptions in this statistic: the flat-sky (small angle limit), the Limber (Bessel-to-delta…

The Quasi-Steady-State Cosmology as proposed by Hoyle, Burbidge and Narlikar does not fit the observed facts of the Universe. In particular, it predicts that 75-90\% of the radio sources in the brightest sample that shows steeper than…

We cross-correlate the new 3 year Wilkinson Microwave Anistropy Probe (WMAP) cosmic microwave background (CMB) data with the NRAO VLA Sky Survey (NVSS) radio galaxy data, and find further evidence of late integrated Sachs-Wolfe (ISW) effect…

We present forecasts for constraints on cosmological models which can be obtained by forthcoming radio continuum surveys: the wide surveys with the LOw Frequency ARray (LOFAR), Australian Square Kilometre Array Pathfinder (ASKAP) and the…