News: SDSU students take on Annual APS Meeting in the Mile High City.

News:  Ph.D students Micah Schuster and Omair Zubairi along with Postdoc Dr. Milva Orsaria will be presenting their work at the Annual APS meeting held this April in Denver, CO.  See below for their abstracts.

Micah Schuster:

Abstract:

Working within the no-core shell model approach with a similarity renormalization group (SRG) evolved two- and three-nucleon (NN+NNN) Hamiltonian, we compute the dipole strength function of 4He, using the Lorentz integral transform (LIT) method to obtain the continuum response. We then compute the total photo-absorption cross section of 4He. We pay particular attention to the convergence of the total strength and of the LIT of the dipole response as we increase the size of the harmonic oscillator basis.

Omair Zubairi

Abstract:

In recent years, scientists have made the discovery that the expansion rate of the Universe is increasing rather than decreasing. This acceleration leads to an additional term in Albert Einstein’s field equations which describe general relativity and is known as the cosmological constant. This work explores the aftermath of a non-vanishing cosmological constant for relativistic spherically symmetric mass distributions, which are susceptible to change against Einstein’s field equations. We introduce a stellar structure equation known as the Tolman-Oppenhiemer-Volkoff (TOV) equation modified for a cosmological constant, which is derived from Einstein’s modified field equations. We solve this modified TOV equation for these spherically symmetric mass distributions and obtain stellar properties such as mass and radius and investigate changes that may occur depending on the value of the cosmological constant.

Dr. Milva Orsaria

Abstract:

Using a nonlocal extension of the SU(3) Nambu-Jona Lasinio model, which reproduces several of the key features of Quantum Chromodynamics, we show that mixed phases of deconfined quarks and confined hadrons (quark-hybrid matter) may exist in the cores of neutron stars as massive as around 2.1M⊙. According to our study, the implications for the recently discovered, massive neutron star PSR J1614–2230, whose gravitational mass is 1.97±0.04M⊙, are that this neutron star may contain an extended region of quark-hybrid matter at it center, but no pure quark matter.

 
 
 

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