Structural phase transitions:
Influence of defects; dynamics; central peak
(Landau-Ginzburg theory of disordered systems; renormalization group).
Dynamic critical behavior near equilibrium phase transitions:
Universality classes; anomalies in the ordered phase of isotropic systems;
crossover behavior; stability against non-equilibrium perturbations
(Langevin equations; dynamic field theory; renormalization group).
Phase transitions and scaling in systems far from equilibrium:
Directed percolation; Burgers/Kardar-Parisi-Zhang equation;
branching and annihilating random walks; diffusion-limited reactions;
anomalous diffusion; driven diffusive systems
(Master and Langevin equations; field theory; renormalization group;
Monte Carlo simulations).
NSF "nugget" (powerpoint): Reaction-controlled diffusion
Statistical mechanics of flux lines in superconductors:
Mapping to boson quantum mechanics; influence of correlated disorder;
properties of the Bose glass phase; vortex transport and flux pinning;
critical properties of the normal- to superconducting transition with disorder;
voltage and flux density noise
(Path-integral description; Bogoliubov theory; numerical simulations).
Applications of statistical physics to biological problems:
Glassy properties of prokaryotic bacteria; receptor-ligand binding kinetics
on cell membranes; predator-prey population dynamics -> movies
(Mean-field and Smoluchowski theory; Monte Carlo simulations).
NSF "nuggets" (powerpoint): Correlations in chemical reaction kinetics
Complex patterns and fluctuations in stochastic lattice models for predator-prey competition and coexistence
Stochastic lattice models for predator-prey coexistence and host-pathogen competition
My research has in the past been funded by the Deutsche
the European Commission TMR program, the U.S. National Science Foundation,
and the Jeffress Memorial Trust.
Current funding through the U.S. Department of Energy, Office of Basic Energy
Sciences under grant no. DE-FG02-09ER46613 is gratefully acknowledged.
Obituary Prof. Dr. Franz Schwabl (1938 - 2009)
Luxembourg summer school "Ageing and the Glass Transitions", Luxemburg,
Lecture notes Field theory approaches to nonequilibrium dynamics;
published in Springer Lecture Notes in Physics 716
Isaac Newton Institute School
Non-equilibrium dynamics of interacting particle systems, Cambridge, U.K., March 27 - April 7, 2006:
Lecture notes Field-theoretic approaches to interacting particle systems
Mechanics Conference, Rutgers University, May 6-8, 2007:
Invited talk Current distribution in driven diffusive systems
Complexity in materials far from equilibrium,
Virginia Tech, Blacksburg, Virginia, USA, May 14 - 16, 2008,
funded through the US National Science Foundation, the Sowers Foundation, and Virginia Tech.
NSF highlight (powerpoint): Complexity in materials far from equilibrium
Second annual French complex systems summer school,
Lyon and Paris, France, July 15 - August 10, 2008
Fluctuations and correlations in complex systems: An introduction to stochastic nonlinear dynamics
school for condensed matter and materials physics:
Nonequilibrium statistical mechanics - fundamental problems and applications,
Boulder, Colorado, USA, July 6 - 24, 2009
EPSRC symposium workshop on non-equilibrium dynamics of spatially
extended interacting particle systems (NEQ),
Warwick, U.K., January 11 - 13, 2010: Invited talk
Stochastic predator-prey models: population oscillations, spatial correlations, and the effect of randomized rates
Model and data hierarchies
for simulating and understanding climate: simulation hierarchies for climate
Institute for Pure and Applied Mathematics (IPAM), UCLA, Los Angeles, California, USA, May 3 - 7, 2010:
Invited talk (powerpoint) Stochastic fluctuations and emerging correlations in simple reaction-diffusion systems
Continuum Models and Discrete
Systems Symposium 12,
Centre for Applied Mathematics and Computational Science, Saha Institute of Nuclear Physics,
Kolkata, India, February 21 - 25, 2011: Invited talk (powerpoint)
Stochastic population oscillations in spatial predator-prey models
Universitätswochen für Theoretische Physik,
Schladming, Austria, February 26 - March 5, 2011: Four lectures
Renormalization Group: Applications in Statistical Physics; lectures 1 & 2; lectures 3 & 4; lecture notes.
Arnold Sommerfeld Center
for Theoretical Physics, Ludwig-Maximilians University Munich,
Sommerfeld Theory Colloquium, December 12, 2012: slides; Nonequilibrium Relaxation and Aging Kinetics (Video)
Office: Virginia Tech, Department of Physics, MC 0435
Address: 901 Drillfield Drive, Robeson Hall, Room 109
Office hours: Monday and Friday 1.15 - 2.15 pm; or by appointment