Higgs Inflation is no doubt one of the most favoured models of inflation in present time. But the huge non-minimal coupling of the Higgs field with gravity required for the model to work often raises concern which is dubbed as the 'unitarity problem' of Higgs inflation. We will show that CSL-like collapse dynamics, otherwise applied to inflationary dynamics in order to explain the quantum-to-classical transition of primordial quantum modes, can bring down the value of non-minimal coupling considerably.

The inflationary paradigm is the most successful model for the
generation of primordial perturbations. These perturbations have a
purely quantum origin, while the inhomogeneities and anisotropies
observed today exhibit a classical behavior. The model called Continuous
Spontaneous Localization (CSL) is a proposed mechanism to solve the
measurement problem in quantum mechanics. In this presentation, we will
analyze the theoretical predictions resulting from incorporating the CSL

Inflationary models in non-trivial field spaces encoded by their non-canonical kinetic terms have attracted attentions recently. We have then extended the so-called stochastic formalism to such a general case. This formalism investigates the fluctuation of inflatons treating them as Brownian motions. This work highlights the involved problem of this formalism, related with the mathematical uncertainty of the definition of noise integral. Comparing the correlation functions in the stochastic formalism and quantum field theory, we clarify that this uncertainty cannot be rem

Scalar-tensor theories serve models for inflation and dark energy. Many efforts have been made recently for constructing the most general scalar-tensor theories with higher-order derivatives in their Lagrangian. Since higher-derivative theories are typically associated with Ostrogradsky ghost which causes unbounded Hamiltonian, it is important to clarify how to evade it.

Within a broken local gauge vector-like $SU(3)_F$ family symmetry, we address the problem of quark masses and mixing,  and study some rare flavor violating processes induced by the new gauge bosons, which can generate transitions between different families and so introduce "Flavor Changing Neutral Currents"(FCNC) couplings at tree level. We find out that some of the most dangerous FCNC processes, like for instance;