Inflation in mimetic $f(R,T)$ gravity

TL;DR

This paper explores inflationary solutions within mimetic $f(R,T)$ gravity, demonstrating that specific models can produce cosmologies consistent with recent observational data by adjusting Lagrange multipliers and potentials.

Contribution

It introduces three new inflationary solutions in mimetic $f(R,T)$ gravity compatible with Planck and BICEP2/Keck data, using a minimal $f(R,T)$ model with adjustable parameters.

Findings

Viable inflationary solutions match observational constraints.

Adjusting Lagrange multiplier and mimetic potential yields compatible cosmologies.

Three distinct Hubble parameter models are proposed.

Abstract

In this paper, we employ mimetic $f(R,T)$ gravity coupled with Lagrange multiplier and mimetic potential to yield viable inflationary cosmological solutions consistent with latest Planck and BICEP2/Keck Array data. We present here three viable inflationary solutions of the Hubble parameter ($H$) represented by $H(N)=\left(A \exp \beta N+B \alpha ^N\right)^{\gamma }$, $H(N)=\left(A \alpha ^N+B \log N\right)^{\gamma }$, and $H(N)=\left(A e^{\beta N}+B \log N\right)^{\gamma }$, where $A$, $\beta$, $B$, $\alpha$, $\gamma$ are free parameters, and $N$ represents the number of e-foldings. We carry out the analysis with the simplest minimal $f(R,T)$ function of the form $f(R,T)= R + \chi T$, where $\chi$ is the model parameter. We report that for the chosen $f(R,T)$ gravity model, viable cosmologies are obtained compatible with observations by conveniently setting the Lagrange multiplier and the mimetic potential.