Relativistic effects on galaxy number counts

Relativistic effects on galaxy number counts: gravitational waves and frame draggings 

علیرضا اله یاری (دانشکده فیزیک دانشگاه صنعتی شریف)

 

Abstract: A key probe to discriminate cosmological models is their bispectrum as non-Gaussian initial conditions are imprinted on the primordial bispectrum. However, it is known that the observed value of the galaxy number density is different than its primordial value by projection effects.  In this talk, I will briefly review the formalism for these projection effects. I will then derive the  bispectrum  including vector (frame draggings) and gravitational wave perturbations. These vector and tensor modes are generated at second order. We show that the contribution of vectors and tensors is ~1 percent at redshift  z=1 on  scales ~300Mpc.

 

 یکشنبه ۲۱ آبان ماه ۱۳۹۶، ساعت ۱۵:۰۰

دانشکده فیزیک، تالارپرتوی

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