Related papers: Detecting dark energy with wavelets on the sphere
I present to this conference our latest measurements of the integrated Sachs-Wolfe (ISW) effect. After a brief review of the reasons for which this effect arises and of the technique to detect it by cross-correlating the cosmic microwave…
The true nature of dark energy remains unclear: It is either a strange fluid in the Universe, with a negative effective pressure, or a breakdown in General Relativity on large scales. This question can only be answered through a suite of…
The integrated Sachs-Wolfe (ISW) effect in the cosmic microwave background (CMB) as measured through its correlation with galaxies provides a unique opportunity to study the dynamics of the dark energy through its large scale clustering…
We investigate the possibility of constraining dark energy with the Integrated Sachs Wolfe effect recently detected by cross-correlating the WMAP maps with several Large Scale Structure surveys. In agreement with previous works, we found…
Dark energy perturbations are normally either neglected or else included in a purely numerical way, obscuring their dependence on underlying parameters like the equation of state or the sound speed. However, while many different…
The variation of dark energy density with redshift, $\rho_X(z)$, provides a critical clue to the nature of dark energy. Since $\rho_X(z)$ depends on the dark energy equation of state $w_X(z)$ through an integral, $\rho_X(z)$ can be…
The characterisation of dark energy is one of the primary goals in cosmology especially now that many new experiments are being planned with the aim of reaching a high sensitivity on cosmological parameters. It is known that if we move away…
We report the detection of dark energy near the Milky Way made with precision observations of the local Hubble flow of expansion. We estimate the local density of dark energy and find that it is near, if not exactly equal to, the global…
Weak lensing convergence statistics is a powerful tool to probe dark energy. Dark energy plays an important role to the structure formation and the effects can be detected through the convergence power spectrum, bi-spectrum etc. One of the…
We study the utility of wavelets for detecting the redshift evolution of the dark energy equation of state w(z) from the combination of supernovae, CMB and BAO data. We show that local features in w, such as bumps, can be detected…
Measurements of the flux and redshifts of Type Ia supernovae have provided persuasive evidence that the expansion of the universe is accelerating. If true, then in the context of standard FRW cosmology this suggests that the energy density…
We review the tantalising prospect that the first evidence for the dark energy driving the observed acceleration of the Universe on giga-parsec scales may be found through metre scale laboratory based atom interferometry experiments. To do…
The phenomenon of dark energy and its manifestations are studied in a spherically symmetric universe considering the Brans-Dicke scalar tensor theory. In the first model the dark energy behaves like a phantom type and in such a universe the…
We show that gravitational lensing can provide a direct method to probe the nature of dark energy at astrophysical scales. For lensing system as an isolated astrophysical object, we derive the dark energy contribution to gravitational…
Understanding the nature of the dark energy is one of the most important task in cosmology. In principle several cosmological observations can be used to discriminate amid a static cosmological constant contribution and a dynamical…
The nature of dark energy remains a profound mystery 20 years after the discovery of cosmic acceleration. A very high number density galaxy redshift survey over a wide area (HD GRS Wide) spanning the redshift range of 0.5<z<4 using the same…
It is shown that the vacuum condensate induced by many phenomena behaves as a perfect fluid which, under particular conditions, has zero or negative pressure. In particular, the condensates of thermal states, of fields in curved space and…
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…
Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. The acceleration of the Universe is, along with dark matter, the observed…
Discoveries in the last few years have revolutionized our knowledge of the universe and our ideas of its ultimate fate. Measurements of the expansion of the universe show that it is not slowing down under normal gravity but accelerating due…