#### Alladi Ramakrishnan Hall

#### The standard model of cosmology and beyond: constraints and forecasts

#### Dhiraj Hazra

##### Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Bologna

*The standard model of cosmology assumes the primordial perturbations to be*

Gaussian and to have a power law spectrum. Supporting observations also

suggest that the Universe consists of baryons, radiation, cold dark matter

and cosmological constant as dark energy. Cosmic Microwave Background (CMB)

temperature and polarization spectra are the best probes till date, to test

most of these assumptions. I will discuss a model independent

reconstruction of the primordial power spectrum directly using the CMB

angular power spectrum data from Planck. Direct reconstruction hints

towards possible features in the data, which in turn indicate non-trivial

inflationary dynamics. I will demonstrate the generation of these features

in the primordial power spectra involving canonical scalar field driven

inflation models, particularly in the Wiggly Whipped Inflation framework. I

will introduce the BI-spectra and Non-Gaussianity Operator (BINGO) for the

efficient numerical computation of the primordial power spectrum and

bi-spectrum. After presenting the recent constraints on the primordial

features, I will discuss the extent to which we will be able to identify

these features with future space based CMB surveys. Introducing poly-reion

(a new free-form parametrization of the history of reionization), I will

present model independent constraints on reionization from CMB and quasar

data. Using this non-standard model of reionization history, I will address

its degeneracies with other cosmological processes in the CMB data. Towards

the end of my talk, in order to examine another assumption of the standard

model, I will discuss a model independent test of the isotropy of the

matter dominated Universe using the Lyman-alpha forest data from the high

redshift quasars.

Done