2025/02/11 by Sourav Bhattacharya, Bhattacharya, Sourav, Sudesh Kumar +1 · 1 citation
Earth and Planetary Sciences · Economics, Econometrics and Finance · Engineering · Mathematics · Physics and Astronomy · #Cosmology and Gravitation Theories #Coupling (piping) #Engineering #Geometry #Geophysics and Gravity Measurements #Mathematical physics #Mathematics #Physics #Quantum mechanics #Scalar (mathematics) #Stochastic processes and financial applications #Theoretical physics #Yukawa potential
paper · pdf · doi:10.48550/arxiv.2502.07428
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2025/02/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider a stochastic spectator scalar field coupled to fermion via the Yukawa interaction, in the inflationary de Sitter background. We consider the fermion to be massless, and take the one loop effective potential found earlier by using the exact fermion propagator in de Sitter spacetime. We take the potential for the spectator scalar to be quintessence-like, V(ϕ)=α|ϕ|p (α\ensuremath> 0, p\ensuremath> 4), so that the total effective potential is generically bounded from below for all values of the parameters and couplings, and a late time equilibrium state is allowed. Using next the stochastic spectral expansion method, we numerically investigate the two point correlation function, as well as the density fluctuations corresponding to the spectator field, with respect to the three parameters of the total effective potential, α, p and the Yukawa coupling, g. In particular, we find that the power spectrum and the spectral index corresponds to blue tilt with increasing g. The three point correlation function and non-Gaussianity corresponding to the density fluctuation has also been investigated. The increasing Yukawa coupling is shown to flatten the peak of the shape function in the squeezed limit. Also in this limit, the increase in the same is shown to increase the local non-Gaussianity parameter.