Secondary non-Gaussianity and Cross-Correlation Analysis (2009)
Munshi, Dipak, Valageas, Patrick, Cooray, Asantha, Heavens, Alan
We develop optimised estimators of two sorts of power spectra for fields defined on the sky, in the presence of partial sky coverage. The first is the cross-power spectrum of two fields on the sky;...
Ballistic aggregation for one-sided Brownian initial velocity (2008)
We study the one-dimensional ballistic aggregation process in the continuum limit for one-sided Brownian initial velocity (i.e. particles merge when they collide and move freely between collisions,...
Propagators in Lagrangian space (2008)
Bernardeau, Francis, Valageas, Patrick
It has been found recently that propagators, e.g. the cross-correlation spectra of the cosmic fields with the initial density field, decay exponentially at large-k in an Eulerian description of the...
Using the Zeldovich dynamics to test expansion schemes (2007)
We apply various expansion schemes that may be used to study gravitational clustering to the simple case of the Zeldovich dynamics. Using the well-known exact solution of the Zeldovich dynamics we...
Large-N expansions applied to gravitational clustering (2006)
We develop a path-integral formalism to study the formation of large-scale structures in the universe. Starting from the equations of motion of hydrodynamics (single-stream approximation) we derive...
Relaxation of a 1-D gravitational system (2006)
We study the relaxation towards thermodynamical equilibrium of a 1-D gravitational system. This OSC model shows a series of critical energies $E_{cn}$ where new equilibria appear and we focus on the...
How many SNeIa do we need to detect the effect of weak lensing ? (2006)
Munshi, Dipak, Valageas, Patrick
We show that as many as 4000 SNeIa may be required to detect the effect of weak lensing on their flux distribution with a high level of significance. However, if the intrinsic SNeIa magnitude...
Thermodynamics and dynamics of a 1-D gravitational system (2006)
We describe a one-dimensional self-gravitating system derived from the problem of large-scale structure formation in cosmology. Considering small times so that the expansion can be neglected we...
Munshi, Dipak, Valageas, Patrick
We study the possibility of using the entire probability distribution function (PDF) of the aperture mass Map and its related cumulative probability distribution function (CPDF) to obtain meaningful...
Cosmological Constraints from Weak Lensing Surveys (2005)
Munshi, Dipak, Valageas, Patrick
Focusing on the well motivated aperture mass statistics $\Map$, we study the possibility of constraining cosmological parameters using future space based SNAP class weak lensing missions. Using...
Cosmology with Weak Lensing Surveys (2005)
Munshi, Dipak, Valageas, Patrick
Weak gravitational lensing surveys measure the distortion of the image of distant sources due to the deflections of light rays by the fluctuations of the gravitational potential along the line of...
Covariance of Weak Lensing Observables (2004)
Munshi, Dipak, Valageas, Patrick
Analytical expressions for covariances of weak lensing statistics related to the aperture mass $\Map$ are derived for realistic survey geometries such as SNAP for a range of smoothing angles and...
On Cross-correlating Weak Lensing Surveys (2004)
Munshi, Dipak, Valageas, Patrick
The present generation of weak lensing surveys will be superseded by surveys run from space with much better sky coverage and high level of signal to noise ratio, such as SNAP. However, removal of...
Evolution of the Cosmological Density Distribution Function: A New Analytical Model (2004)
Valageas, Patrick, Munshi, Dipak
The one-point probability distribution function (pdf) of the large-scale density field is an important tool to follow the evolution of cosmological structures. In this paper we present a new model...
On the estimation of gravity-induced non-Gaussianities from weak lensing surveys (2004)
Valageas, Patrick, Munshi, Dipak, Barber, Andrew J.
We study various measures of weak lensing distortions in future surveys, taking into account the noise arising from the finite survey size and the intrinsic ellipticity of galaxies. We also consider...
Weak lensing shear and aperture-mass from linear to non-linear scales (2003)
Munshi, Dipak, Valageas, Patrick, Barber, Andrew J.
In this paper we describe the predictions for the smoothed weak lensing shear and aperture-mass of two simple analytical models of the density field: the minimal tree-model and the stellar model....
Barber, Andrew J., Munshi, Dipak, Valageas, Patrick
Weak lensing convergence can be used directly to map and probe the dark mass distribution in the universe. Building on earlier studies, we recall how the statistics of the convergence field are...
Analytical Predictions for Statistics of Cosmic Shear: Tests Against Simulations (2003)
Valageas, Patrick, Barber, Andrew J., Munshi, Dipak
Weak gravitational lensing surveys are rapidly becoming important tools to probe directly the mass density fluctuations in the universe and its background dynamics. Earlier studies have shown that it...
The Mass and Luminosity Functions of Galaxies and their Evolution (1998)
Valageas, Patrick, Schaeffer, Richard
We set up a model for the evolution of the galaxy luminosity function, taking advantage of recent work that brought in some better understanding of the mass function for gravitationally condensed...
The Multiplicity Function of Galaxies, Clusters and Voids (1997)
Valageas, Patrick, Schaeffer, Richard
We calculate the multiplicity function of matter condensations by directly considering the actual, deeply non-linear density field, which we compare to the popular Press-Schechter approximation. We...