Moustafa Sayem El-Daher

arXiv2023

On Warm Natural Inflation and Planck 2018 constraints

We investigate Natural Inflation with non-minimal coupling to gravity, characterized either by a quadratic or a periodic term, within the Warm Inflation paradigm during the slow roll stage, in both strong and weak dissipation limits, and show that, in the case of $T$-linearly dependent dissipative term, it can accommodate the spectral index $n_s$ and tensor-to-scalar ratio $r$ observables given by Planck 2018 constraints, albeit with a too small value of the e-folding number to solve the horizon problem, providing thus only a partial solution to Natural Inflation issues. Assuming a $T$-cubically dependent dissipative term can provide a solution to this e-folding number issue.

gr-qc↗

arXiv2020

The Inverse Problem for Simple Liquid Metals a Study Case on Liquid Aluminum at Melting Point

In an attempt to test the possibility of solving the inverse problem for liquid metals i.e. obtaining the effective pair potential from the experimental structure factor, we solve the modified Hypernetted-Chain Integral equation for liquid aluminum at melting temperature to obtain the effective pair potential starting from the experimental structure factor and compare it with the potential obtained from theoretical considerations. Then we use the potential obtained by solving the inverse problem in Monte Carlo simulation to test it, and the calculated structure factor of the liquid aluminum is compared with experiment. We show that the solution of the inverse problem in such cases gives reasonable quantitative results, and reproduces the general features of the pair potential and the results for the structure factor are not far from the experimental measurements.

cond-mat.stat-mech↗