Ph.D. Students Head South for Annual APS Conference


Micah Schuter (left) & Omair Zubairi (right) enjoying a sunny day at the Savannah Convention Center Harbor

Ph.D. Students Micah Schuster and Omair Zubairi head off to beautiful Savannah, GA for the annual APS April meeting.  Micah Schuster works in the field of Nuclear Physics with Professor Calvin Johnson.  Omair Zubairi’s research is in the field of Astrophysics and General Relativity, he works with Professor Fridolin Weber.  Both students won the graduate travel grants awarded by APS every year.  Shuster for Division of Nuclear Physics (DNP) and Zubairi for Division of Astrophysics (DAP).  See below for their abstracts:



Micah Schuster:

Operator evolution in the three-body space via the similarity renormalization group

Performing quantitative calculations of nuclear observables is a guiding principle of nuclear theory. Computationally, this is complicated by the large model spaces needed to reach convergence in many-body approaches, such as the no-core shell model (NCSM). In recent years, the similarity renormalization group (SRG) has provided a powerful tool to soften interactions for ab initio structure calculations, thus leading to convergence within smaller model spaces. SRG has been very successful when applied to the Hamiltonian of the nuclear system. However, when computing observables other than spectra, one must evolve the relevant operators using the same transformation that was applied to the Hamiltonian. Here we compute the root mean square (RMS) radius of 3H to show that evolving the r2 operator in the three-body space, thus including two- and three-body SRG induced terms, will yield an exactly unitary transformation. We then extend our calculations to 4He and compute the RMS radius and total strength of the dipole transition using operators evolved in the three-body space.

Omair Zubairi:

“Non-Spherical Stellar Models of Compact Stars”

Conventionally, the structure of compact stellar objects such as neutron or quark stars are modeled with the assumption that they are perfect spheres. However, due to high magnetic fields, certain classes of compact stars (such as magnetars and neutron stars containing cores of color-superconducting quark matter) are expected to be deformed (non-spherical) making them ob-longed spheroids. In this work, we seek to investigate the stellar structure of these such de-formed compact objects in the framework of general relativity. Using a metric that describes a non-spherical mass distribution, we derive the stellar structures equations of these non-spherical compact objects. Since we do not have spherical symmetry, we need to take into the account the pressure gradient not only in the radial but in the polar direction as well. We then calculate stellar properties such as mass and radii along with density and pressure profiles for neutron stars with high magnetic fields and investigate any changes from the standard spherical models.





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