Theoretical and Computational Physics

Martin Bier does theoretical work involving thermodynamics, dynamical systems, complex networks, and stochastic processes.  Through a combination of computer simulations, acquisition of data, and theoretical approximations, our group tries to understand why and how systems behave the way they do.  In this way we analyze the propagation of infectious disease, the transduction of energy through biomolecules, the transfer of stocks, etc.

Dr. Bier’s homepage

“Maxwell’s Demon” is a thought experiment that was first proposed 150 years ago. Later variations on Maxwell’s idea, like the one in the figure, are called “Maxwell Zombies.

Dr Michael Dingfelder is interested to understand how ionizing radiation interacts with matter of biological interest. This includes calculating interaction cross sections, developing transport models, and implementing them into Monte Carlo track-structure simulation codes. These codes are used to simulate and predict initial radiation damage to biological targets, such as DNA or cell constituents. DNA single and double strand breaks in large number are considered essential for cell killing, e.g., in radiotherapy. Misrepaired DNA damage, on the other hand can lead to mutations and the onset of cancer.
Dr. Gregory Lapicki compiles and calculates x-ray production cross sections (XRPCS) for protons and other ions that produce x-rays in atomic inner shells.  These XRPCS are required for reliable analyses of elemental composition and concentration of materials as it is done with the particle-induced x-ray emission (PIXE) technique.  He has developed the ECUSAR theory which is in excellent agreement with L-shell XRPCS for protons. In further studies, he plans to extend this work to K- and M-shell ionizations by protons and heavier ions.

Compiled data for 5771 total L-shell XRPCS for proton energies 26 eV≤E1≤ 1 GeV and all elements with 24≤Z≤95 and universal fit.

Collision of two gold nuclei at high energy as calculated from A Multi-Phase Transport (AMPT) model. Length of the box is 60fm=6×10-14 m; time covers the first 30fm/c=10-22 s

Dr. Zi-Wei Lin does research in theoretical and computational physics. His research interests includes

  1. theoretical high energy heavy ion physics and development of Monte Carlo transport models,
  2. radiation physics and space radiation protection,
  3. medical physics on pseudo-CT methods for MRI-only radiotherapy.

These projects have involved undergraduate and  graduate students, postdoctoral researchers, visiting students, and visiting professors.

Dr. Lin’s ECU research homepage