My research focuses on applications of renormalization group (RG) and effective field theory (EFT) methods to the microscopic description of nuclei and nuclear matter. EFT and RG methods have long enjoyed a prominent role in condensed matter and high energy theory due to their power of simplification for strongly interacting multi-scale systems. More recently, these complementary techniques have become widespread in low-energy nuclear physics, enabling the prospect for model-independent calculations of nuclear structure and reactions with controllable theoretical errors and providing a more tangible link to the underlying quantum chromodynamics.
From a computational perspective, the use of EFT and RG techniques substantially simplifies many-body calculations by restricting the necessary degrees of freedom to the energy scales of interest. In addition to extending the reach of ab-inito calculations by eliminating unnecessary degrees of freedom, many problems become amenable to simple perturbative treatments. Since a mean-field description now becomes a reasonable starting point for nuclei and nuclear matter, it becomes possible to provide a microscopic foundation for extremely successful (but largely phenomenological) methods such as the nuclear shell model and nuclear density functional theory (DFT) that are used to describe properties of the medium-mass and heavy nuclei where ab-inito methods are computationally prohibitive. The use of RG and EFT methods to construct effective nuclear shell model Hamiltonians and energy density functionals from the underlying nuclear force in a major component of the DOE-funded Scientific Discovery thru Advanced Computing (SciDAC) project "Nuclear Computational Low-Energy Initiative (NUCLEI)" of which I am a member.
My research program presents a diverse range of research opportunities for potential Ph.D. students, encompassing three very different (but interrelated) components that offer a balance of analytical and numerical work: 1) inter-nucleon interactions, 2) ab-initio methods for finite nuclei and infinite nuclear matter, and 3) density functional theory for nuclei.
Specific topics that I am currently interested in are: calculating the equation of state for nuclear matter from microscopic inter-nucleon interactions, exploring the role of three-nucleon forces in neutron-rich nuclei, microscopic construction of shell model Hamiltonians and effective operators, developing microscopically based density functional theory for nuclei, and loosely bound systems at the limits of stability.
Selected PublicationsIn-Medium Similarity Renormalization Group for Open-Shell Nuclei, K. Tsukiyama, S.K. Bogner and A. Schwenk, Phys.Rev. C 85, 061304 (2012).
Testing the density matrix expansion against ab-initio calculations of trapped neutron drops, S.K. Bogner et al., Phys. Rev. C 84, 044306 (2011).
In-medium similarity renormalization group for nuclei, K. Tsukiyama, S.K. Bogner and A. Schwenk, Phys. Rev. Lett. 106, 222502 (2011).
From low-momentum interactions to nuclear structure, S.K. Bogner, R.J. Furnstahl and A. Schwenk, Prog. Part. Nucl. Phys. 65, 94 (2010).