MR. VIKRAM KHAIRE

The recent claim of 'photon underproduction crisis' suggests that the known sources of ultra-violet (UV) radiation in the local Universe may not be sufficient to generate the inferred hydrogen ionizing background. Findings of it implies that more than 80% of UV background is contributed by unknown sources such as low luminosity hidden QSOs or decaying dark matter particles. In our recent work we investigate these claims and provide a simple solution. I will discuss the method to estimate the UV background, contributions of different sources to it and the solution to photon underproduction crisis.