Speaker
Description
On very large scales in the Universe is the observed matter is distributed into galaxies, clusters of galaxies and superclusters with large void spaces in between. This spider-web like pattern of matter is very loosely referred to as large scale structure. This
structure is believed to have grown from tiny seed density perturbations laid down during the inflationary era in the history of the Universe. This evolution depends sensitively upon various parameters that describe the initial conditions and the overall expansion history of the Universe and, indeed, most modern observational surveys aim to map this large scale structure with the primary aim of constraining these cosmological parameters.
In order to carry out this exercise, one needs robust theoretical predictions. While, N-body simulations do a great job at tracking this structure, they have certain limitations. Firstly, they are computationally expensive and given the wide range of cosmological models, exploring the parameter space can become prohibitive. Additionally, they use a discrete-particle representation to model the density field and hence are shot-noise limited. This can be a hindrance particularly, while exploring primordial non-gaussianities or warm dark
matter models. In this talk we will discuss some alternative methods to model the growth of structure. Although approximate, they can give insights into the physics as well as serve as a complementary techniques to N-body codes.