The paper deals with Warm Inflationary scenario in FLRW with torsion both from theoretical and observational point of view. In the background of flat FLRW model the Hubble parameter is found to be proportional to the torsion function and warm inflation is examined both in weak and strong dissipation regimes for the power law choice of potential using slow-roll approximation with quasi-stable criteria for radiation. The slow-roll parameters, no.of e-folds, scalar spectral index, and tensor-to-scalar ratio are determined in the present model for mainly three choices of the dissipation coefficient  $$\Gamma $$  <math> <mi>Γ</mi> </math>   using the Planck data set. Finally, we focus on single-field chaotic quartic potential with the above choices of the dissipation coefficient to confront the warm inflation observational predictions directly with the latest observational data set.

India

Madhukrishna Chakraborty

Gopal Sardar

Akash Bose

Subenoy Chakraborty

Theoretical and observational prescription of warm-inflation in FLRW universe with torsion

The present cosmological model deals with modified f(R, T) gravity theory with  $$f(R,T)=R+h(T)$$  <math> <mrow> <mi>f</mi> <mo>(</mo> <mi>R</mi> <mo>,</mo> <mi>T</mi> <mo>)</mo> <mo>=</mo> <mi>R</mi> <mo>+</mo> <mi>h</mi> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> </math>   in the background of homogeneous and isotropic FLRW space-time model. Four choices of h(T) have been studied and examined from two observational data sets. It is found that model III, namely, the linear combination of power law and logarithmic form is more consistent with observed data than the others. However, all four considered models are a worse fit than the LCDM model.

Observational constraints on f(R, T) gravity with  $$f(R,T) = R + h(T)$$  <math> <mrow> <mi>f</mi> <mo>(</mo> <mi>R</mi> <mo>,</mo> <mi>T</mi> <mo>)</mo> <mo>=</mo> <mi>R</mi> <mo>+</mo> <mi>h</mi> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> </math>

In previous work, it had been shown that polymer quantized scalar field theory predicts that even an inertial observer can experience spontaneous excitations. This prediction was shown to hold at low energies. However, in these papers it was assumed that the polymer scale is constant. But it is possible to relax this condition and obtain a larger class of theories where the polymer scale is a function of momentum. Does the prediction of low energy Lorentz violation hold for all of these theories? In this paper we prove that it does. We also obtain the modified rates of radiation for some of these theories.