M. Ronen Plesser

M. Ronen Plesser

Professor in the Program in Education

External address: 
245 Physics Bldg, 120 Science Drive, Durham, NC 27708
Internal office address: 
Box 90305, Department Of Physics, Durham, NC 27708-0305
(919) 660-9668


My research is in String Theory, the most ambitious attempt yet at a comprehensive theory of the fundamental structure of the universe. In some (rather imprecise) sense, string theory replaces the particles that form the fundamental building blocks for conventional theories (the fields, or wave phenomena, we observe are obtained starting from particles when we apply the principles of quantum mechanics) with objects that are not point-like but extended in one dimension – strings. At present, the theory is not precisely formulated, as we still seek the conceptual and technical tools needed. The structures we do have in hand suggest that, when formulated precisely, the theory will provide a consistent framework encompassing the two greatest achievements of twentieth century theoretical physics: Einstein’s general theory of relativity, which describes gravitational forces objects in terms of deformations of the geometry of spacetime; and quantum mechanics, a model of fundamental physics in which microscopic objects exhibit the properties of particles under some circumstances and those of waves under others. Both of these theories have been tested with extraordinary precision and yield predictions that agree with our observations of the physical universe. Relativistic effects are manifest at the largest scales in the universe, in the interactions of stars, galaxies, etc. The differences between a quantum mechanical description and a classical nineteenth century description of these objects are so small they can be neglected. Quantum effects dominate at the smallest scales – atoms and their constituents. In this realm, the effects of gravitation can be completely neglected. And yet, under extreme conditions of density, such as may obtain in the final instant of the evaporation of a black hole, both kinds of effects are important. A universal theory of physics thus requires a consistent quantum theory of gravity. Thus far, string theory is the most promising candidate for producing such a theory. Investigations of this theory have already yielded rich insights, and continue to produce more.

My own research centers on the crucial role played in the theory by geometric structures. There is an obvious role for geometry in a theory that incorporates gravitation, which as discussed above is tantamount to the geometry of spacetime. Related to this are several other, less obvious, geometric structures that play an important role in determining the physics of the theory. Indeed, advances in mathematics and in the physics of string theory have often been closely linked. An example of how the two fields have interacted in a surprising way is the ongoing story of mirror symmetry.


  • Ph.D., Harvard University 1991
  • M.A., Harvard University 1988


Ginsparg, P, Goulian, M, Plesser, MR, and Zinn-Justin, J. "(p, q) string actions." Nuclear Physics B 342.3 (October 1990): 539-563. Full Text

Greene, BR, and Plesser, MR. "Duality in Calabi-Yau moduli space." Nuclear Physics B 338.1 (July 1990): 15-37. Full Text

Moore, G, and Plesser, R. "Classical scattering in (1 + 1)-dimensional string theory(Published online)." Physical Review D 46.4: 1730-1736. Full Text

Beasley, CE, and Plesser, MR. "Toric Duality Is Seiberg Duality." JHEP 0112: 001-. Full Text

Aspinwall, PS, and Plesser, MR. "D-branes, discrete torsion and the McKay correspondence(Published online)." Journal of High Energy Physics 2001.02: 009-009. Full Text

Aspinwall, PS, and Plesser, MR. "Heterotic string corrections from the dual type II string(Published online)." Journal of High Energy Physics 2000.04: 025-025. Full Text

Aspinwall, PS, and Plesser, MR. "T-duality can fail(Published online)." Journal of High Energy Physics 1999.08: 001-001. Full Text

Morrison, DR, Narayan, K, and Plesser, MR. "Localized tachyons inC3/ZN(Published online)." Journal of High Energy Physics 2004.08: 047-047. Full Text

Melnikov, IV, and Plesser, MR. "The Coulomb branch in gauged linear sigma models(Published online)." Journal of High Energy Physics 2005.06: 013-013. Full Text