Gregory Puleo

Research

The following are writeups of some research I've done, in various states of completion and comprehensibility. Unless otherwise specified, none of these papers have been formally published (they would perhaps more properly be called manuscripts). All files are in pdf format.
  • Environmental Evolutionary Graph Theory
    • Abstract. We consider a simple stochastic spatial model of competition between two species. The environment is represented by a graph with red and blue vertices, which offer different levels of reproductive fitness to the two species. We derive a simple closed-form solution for the fixation probabilities in the special case where the graph is properly two-colored.
    • Remarks. Most of this work was done during the 2007 REU program at the University of Illinois at Urbana-Champaign, under the mentorship of Robert Muncaster.
  • Reconfigurable Systems and Intractability
    • Abstract. Ghrist and Peterson have investigated the properties of a certain general class of reconfigurable systems, with an eye to practical application. We show that in the general case, these reconfigurable systems are powerful enough to represent the rewriting rules of finitely presented groups, and therefore fall prey to the existence of finitely presented groups with unsolvable word problem.
    • Remarks. This paper was written as part of the 2008 REU program at UIUC, under the mentorship of Kim Whittlesey.