arXiv subjects

Shikha Srivastava

Publications and source records attributed to Shikha Srivastava.

6 recordsLinked to original sources

arXiv2021

New Tsallis holographic dark energy with apparent horizon as IR-cutoff in non-flat Universe

New Tsallis holographic dark energy with apparent horizon as IR-cutoff studied by considering non-flat Friedmann-Lemaitre-Robertson-Walker metric. The accelerating expansion phase of the Universe is described by using deceleration parameter, equation of state parameter and density parameter by using different values of NTHDE parameter "$δ$". The NTHDE Universe's transition from a decelerated to an accelerated expanding phase is described by the smooth graph of deceleration parameter. Depending on distinct values of Tsallis parameter "$δ$", we have explored the quintessence behavior of the equation of state parameter. We used Hubble data sets obtained using Cosmic Chronometric methods and distance modulus measurement of Type Ia Supernova to fit the NTHDE parameters. Stability of our model by analyzing the squared speed of sound investigated as well.

physics.gen-ph↗

arXiv2021

The cosmological behaviour and the statefinder diagnosis for the New Tsallis agegraphic dark energy

In this work, we have considered the recently proposed new Tsallis Agegraphic Dark Energy model (NTADE) (Mod. Phys. Lett. A 34, 1950086, 2019) within the framework of a flat Friedmann-Robertson-Walker(FRW) Universe by taking various values of the parameter $δ$. The NTADE model shows the current phase transition of the Universe from decelerated to accelerated phase. The NTADE EoS parameter shows a rich behaviour as it can be quintessence-like or phantom-like depending on the value of $δ$. For discriminating the NTADE model from $Λ$CDM, we have plotted the statefinder parameters $r(z)$, $s(z)$ and $(r, s)$, $(r, q)$ pair. The NTADE model shows distinct evolutionary trajectories of their evolution in ($ r, s$) and ($ r, q$) plane. An analysis using the snap parameter and the $ω_{D}-ω_{D}^{'}$ pair dynamical analysis have also been performed.

gr-qc↗

arXiv2021

Exploring the new Tsallis agegraphic dark energy with interaction through statefinder

In this work, we explore the recently proposed new Tsallis agegraphic dark energy model in a flat FLRW Universe by taking the conformal time as IR cutoff with interaction. The deceleration parameter of the interacting new Tsallis agegraphic dark energy model provides the phase transition of the Universe from decelerated to accelerated phase. The EoS parameter of the model shows a rich behaviour as it can be quintessence-like or phantom-like depending on the interaction ($b^2$) and parameter $B$. The evolutionary trajectories of the statefinder parameters and $(ω_D, ω_D^{'})$ planes are plotted by considering the initial condition $Ω_{D}^{0} =0.73$, $H_{0}= 67$ according to $Λ$CDM observational Planck 2018 data for different $b^2$ and $B$. The model shows both quintessence and Chaplygin gas behaviour in the statefinder $(r, s)$ and $(r, q)$ pair planes for different $b^2$ and $B$.

gr-qc↗

arXiv2020

Barrow holographic dark energy with Hubble horizon as IR cutoff

In this work, we propose a non-interacting model of Barrow holographic dark energy (BHDE) using Barrow entropy in a spatially flat FLRW Universe considering the IR cutoff as the Hubble horizon. We study the evolutionary history of important cosmological parameters, in particular, EoS $(ω_{B})$, deceleration parameter and, the BHDE and matter density parameter and also observe satisfactory behaviours in the BHDE the model. In addition, to describe the accelerated expansion of the Universe the correspondence of the BHDE model with the quintessence scalar field has been reconstructed.

physics.gen-ph↗

arXiv2011

The probability analysis of opening of DNA

We have studied the separation of a double stranded DNA (dsDNA), which is driven either by the temperature or force. By monitoring the probability of opening of entire base pairs along the chain, we show that the opening of a dsDNA depends not only on the sequence but also on the constraints on the chain in the experimental setups. Our results clearly demonstrate that the force induced melting of dsDNA, whose one of the ends is constrained, is significantly different from the thermal melting, when both ends free.

cond-mat.soft↗

arXiv2008

Dynamics of a bubble formed in double stranded DNA

We study the fluctuational dynamics of a tagged base-pair in double stranded DNA. We calculate the drift force which acts on the tagged base-pair using a potential model that describes interactions at base pairs level and use it to construct a Fokker-Planck equation.The calculated displacement autocorrelation function is found to be in very good agreement with the experimental result of Altan-Bonnet {\it et. al.} Phys. Rev. Lett. {\bf 90}, 138101 (2003) over the entire time range of measurement. We calculate the most probable displacements which predominately contribute to the autocorrelation function and the half-time history of these displacements.

cond-mat.soft↗