Astrophysical signatures of scalar field dark matter in Neutrino and Axion sector

From cosmological observations we know that DM must display clustering properties similar to CDM, at least on the largest scales. However, the particle nature of DM is still not known. The linear LSS observations, such as WiggleZ, BOSS, and Planck data on CMB temperature and polarisation anisotropies can be used to place very stringent constraints on any dark matter models that show deviation from the ΛCDM model for k < 0.1 Mpc−1. However, at smaller scales the situation remains unclear from astrophysical observables, e.g. the missing satellite problem and too big to fail problem are still need to be addressed. This points to a need to study plausible dark matter models that allow for significant deviation from ΛCDM models at small scales and confront them with astrophysical and cosmological observables. I will discuss two class of such models ( Ultra light axion (ULA) and late forming dark matter (LFDM)) where dark matter is produced by scalar field driven phase transition in early universe. I will also discuss their particle physics origin and astrophysical signatures.