arXiv subjects

Hira Sohail

Publications and source records attributed to Hira Sohail.

4 recordsLinked to original sources

arXiv2023

Reconstruction of symmteric teleparallel gravity with energy conditions

This research investigates the impact of modified gravity on cosmic scales, focusing on $f(Q)$ cosmology. By applying energy conditions, the study reconstructs various $f(Q)$ models, considering an accelerating Universe, quintessence, and a cosmological constant $Λ$. Using up-to-date observational data, including the Supernova Pantheon sample and cosmic chronometer data, Hubble constants $H_0$ are estimated as $70.37^{+0.84}_{-0.92}$ km/sec/Mpc (from $H(z)$ data) and $70.02^{+0.44}_{-0.25}$ km/sec/Mpc (from pantheon compilation of SN Ia data). The matter energy density parameter ($Ω_{0m}$) is calculated as $0.26^{0.015}_{-0.010}$(OHD) and $0.27^{0.025}_{-0.014}$(SN Ia). Furthermore, as a function of redshift $z$, explicit expressions of $f(Q)$ and the EOS parameter $ω$ are produced, and their graphical analysis describes the late time acceleration of the Universe without the usage of dark energy.

gr-qc↗

arXiv2023

Models of f(Q) gravity with electromagnetic field

There are so many ideas that potentially explain the dark energy phenomenon, current research is focusing on a more in-depth analysis of the potential effects of modified gravity on both local and cosmic scales. In this paper we have investigated some cosmic reconstructions in $f (Q)$ cosmology where $Q$ is the non-metricity corresponding to the evolution background in the Friedmann-Lamatre-Robertson-Walker $(FLRW)$ universe. This allows us to determine how any $FLRW$ cosmology can emerge from a particular $f (Q)$ theory. We employ the reconstruction technique to generate explicit formulations of the $f (Q)$ Lagrangian for several types of matter sources like perfect fluid, dust like fluid, stiff fluid and the binary mixture of two fluids. Furthermore, we computed the field equations and equation of state (EoS) parameter $ω$ for two different reconstructed $f(Q)$ models with the variation of the involved constants, which gives the scenario of accelerating universe, quintessence region and cosmological constant. We also observed that the time dependence of $ω$ admits cosmic acceleration. These new $f(Q)$ gravity inspired models may have an impact on gravitational phenomena at other cosmological scales.

gr-qc↗

arXiv2023

Quantum Painlevé II Lax Pair and Quantum (Matrix) Analogues of Classical Painlevé II equation

In this article, we present a new quantum Painlevé II Lax pair which explicitly involves the Planck constant $ \hbar $ and an arbitrary field variable $v$ so these two objects make this new pair different from Flaschka-Newell Painlevé II Lax pair and that pair appears as particular case of our's pair which consolidates the Painlevé II equation from quantum mechanical point of view. It is shown that the compatibility of quantum Painlevé II Lax pair simultaneously yields a quantum Painlevé II equation and a quantum commutation relation between field variable $v $ and independent variable $z$. We manifest that with the different choices of arbitrary field variable system reduces to its classical version, matrix Painlevé II equation and derivative matrix Painlevé II equation. Further, we construct the gauge equivalence of quantum Painlevé II Lax pair whose compatibility condition gives rise to quantum p34 equation that involves $\hbar $ with power $+1$ which makes our system more quantized as compared to the existed one that carries $\hbar $ with power $+2$.

math-ph↗

arXiv2023

Darboux Wronskian solutions of Ito typed coupled KdV equation with exact solitonic solutions and conserved densities

In this article, we derive the Darboux solutions of Ito type coupled KdV equation in Darboux framework which is associated with Hirota Satsuma systems. Then we generalise $N$-fold Darboux transformations in terms of Wronskians. We also derive the exact multi-solitonic solutions for the coupled field variables of that system in the background of zero seed solutions. The last section encloses the derivation of continuity equation with several conserved densities through its Riccati equation.

nlin.SI↗