arXiv subjects

Neha Gupta

Publications and source records attributed to Neha Gupta.

58 records · Page 4Linked to original sources

arXiv2013

Pasta phases in neutron star studied with extended relativistic mean field models

To explain several properties of finite nuclei, infinite matter, and neutron stars in a unified way within the relativistic mean field models, it is important to extend them either with higher order couplings or with density-dependent couplings. These extensions are known to have strong impact in the high-density regime. Here we explore their role on the equation of state at densities lower than the saturation density of finite nuclei which govern the phase transitions associated with pasta structures in the crust of neutron stars.

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arXiv2013

Antikaons and higher order couplings in relativistic-mean field study of neutron stars

We investigate the role of higher order couplings, along with the condensation of antikaons ($K^-$ and $\bar K^0$), on the properties of neutron star (NS). We employ extended versions of the relativistic mean-field model, in which kaon-nucleon and nucleon-nucleon interactions are taken on the same footing. We find that the onset of condensation of $K^-$ and $\bar K^0$ highly depends not only on the strength of optical potential but also on the new couplings. The presence of antikaons leads to a softer equation of state and makes the neutron star core symmetric and lepton-deficient. We show that these effects strongly influence the mass-radius relation as well as the composition of neutron star. We also show that the recently observed 1.97$\pm$.04 solar mass NS can be explained in three ways: (i) a stiffer EoS with both antikaons, (ii) a relatively soft EoS with $K^-$ and (iii) a softer EoS without antikaons.

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arXiv2012

Role of higher order couplings in the presence of kaons in relativistic mean field description of neutron stars

We discuss the role of higher order couplings in conjunction with kaon condensation using recent versions of relativistic mean field models.We focus on an interaction (G2) in which all the parameters are obtained by fitting the finite nuclear data and successfully applied to reproduce a variety of nuclear properties. Our results show that the higher order couplings play a significant role at higher densities where kaons dominate the behavior of the equation of state. We compare our results with other interactions (NLl, NL3, G1, and FSUGold) and show that the new couplings bring down the mass of a neutron star (NS), which is further reduced in the presence of kaons to yield results consistent with the present observational constraints. We show that the composition of the NS varies with the parameter sets.

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arXiv2012

Low Power Low Voltage Bulk Driven Balanced OTA

The last few decades, a great deal of attention has been paid to low-voltage (LV) low-power (LP) integrated circuits design since the power consumption has become a critical issue. Among many techniques used for the design of LV LP analog circuits, the Bulk-driven principle offers a promising route towards this design for many aspects mainly the simplicity and using the conventional MOS technology to implement these designs. This paper is devoted to the Bulk-driven (BD) principle and utilizing this principle to design LV LP building block of Operational Transconductance Amplifier (OTA) in standard CMOS processes and supply voltage 0.9V. The simulation results have been carried out by the Spice simulator using the 130nm CMOS technology from TSMC.

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