Burt A. Ovrut

My primary research interests are on the following three areas.

Superstrings and M-Theory:
I have been doing research in this subject since the first "superstring revolution" in the early 1980's. My principal contributions are the following. In Phys. Lett. B158, 1985, I was one of the people to introduce the concept of Wilson lines into heterotic string theory. Wilson lines were used to break the E6 group to smaller, phenomenologically relevant gauge groups. With my student, Gabriel Cardoso, I calculated the non-holomorphic threshold corrections in superstring theory, showing that these corrections are associated with non-perturbative superpotentials. This work appeared in Nuc. Phys. B369, 1992. In hep-th/9710208, my collaborators and I computed the four-dimensional effective action of the strongly coupled heterotic superstring. Important recent research was the construction the "bane world" scenario from M-theory. This work, which appeared in hep-th/9803235 and hep-th/9806051, is a paradigm for phenomenological brane physics derived from fundamental theory, and is now called heterotic M-theory. In hep-th/9912208 it was shown that heterotic M-theory allows vacuum states containing standard-like models of particle physics.

Cosmology:
I have a long standing interest in applying new ideas in particle physics to issues of early universe cosmology. With Paul Steinhardt, I was among the first to introduce supergravity into the theory of inflation. This work appeared in Phys. Lett. B133, 1983. With several collaborators, I presented a theory for the large scale structure of matter based on non-equilibrium phase transitions and percolation theory. This work was published in Nuc.Phys. B434, 1995. In hep-th/9812052 and hep-th/9902071 I explored basic concepts of cosmological expansion and inflation within the context of the strongly coupled heterotic superstring and M-theory brane universes. It has become clear that all the properties of cosmology, including the flatness, horizon and monopole problems, can be addressed using brane collisions in string and M-theory, and do not require a period of inflation. This alternative to inflation, called the Ekpyrotic Universe, was presented in hep-th/0103239, hep-th/0105199 and hep-th/0108187

Geometry of Superstrings:
Much of my research work in both superstrings, M-theory and in cosmology requires new mathematical methods in topology and geometry, particularly algebraic geometry. I have a strong interest in applying this new mathematics to questions of particle physics. In hep-th/9811168 and hep-th/9901009, I showed how grand unified theories can occur on branes by constructing generalized G-instantons on Calabi-Yau threefolds. This work was extended to produce the standard model on a brane world by constructing specialized holomorphic vector bundles. This very technical mathematical physics was presented in hep-th/0008008, math.AG/0008010 and math.AG/0008011. An important mathematical ingredient of Ekpyrotic cosmology is the "small" instanton phase transition, which was presented for brane collisions in hep-th/0001133.

• Professor, University of Pennsylvania, (1990- present)
• Associate Professor, University of Pennsylvania (1985-1990)
• Assistant Professor, The Rockefeller University (1983-1985)
• Member, The Institute for Advanced Study (1980-1983)
• Research Associate, Brandeis University (1978-1980)

• On the Four-Dimensional Effective Action of Strongly Coupled Heterotic String Theory. Andre Lukas, Burt A. Ovrut, Daniel Waldram. Nucl.Phys. B532 (1998) 43-82. hep-th/9710208
• The Universe as a Domain Wall. Andre Lukas, Burt A. Ovrut, K.S. Stelle, Daniel Waldram. Phys.Rev. D59 (1999) 086001. hep-th/9803235
• Heterotic M-theory in Five Dimensions. Andre Lukas, Burt A. Ovrut, K. S. Stelle, Daniel Waldram. Nucl.Phys. B552 (1999) 246-290. hep-th/9806051
• Standard Models from Heterotic M-theory. Ron Donagi (UPenn), Burt A. Ovrut (UPenn), Tony Pantev (UPenn), Daniel Waldram (Princeton University and CERN). Adv.Theor.Math.Phys. 5 (2002) 93-137. hep-th/9912208
• Cosmology and Heterotic M-Theory in Five-Dimensions. Andre Lukas, Burt A. Ovrut, Daniel Waldram. UPR-825T, OUTP-98-85P. hep-th/9812052
• Boundary Inflation. Andre Lukas, Burt A. Ovrut, Daniel Waldram. Phys.Rev. D61 (2000) 023506. hep-th/9902071
• The Ekpyrotic Universe: Colliding Branes and the Origin of the Hot Big Bang. Justin Khoury, Burt A. Ovrut, Paul J. Steinhardt, Neil Turok. Phys.Rev. D64 (2001) 123522. hep-th/0103239
• Visible Branes with Negative Tension in Heterotic M-Theory. Ron Y. Donagi, Justin Khoury, Burt A. Ovrut, Paul J. Steinhardt, Neil Turok. JHEP 0111 (2001) 041. , hep-th/0105199
• From Big Crunch to Big Bang. Justin Khoury, Burt A. Ovrut, Nathan Seiberg, Paul J. Steinhardt, Neil Turok. Phys.Rev. D65 (2002) 086007. hep-th/0108187
• Non-Perturbative Vacua and Particle Physics in M-Theory. Ron Donagi, Andre Lukas, Burt A. Ovrut, Daniel Waldram. JHEP 9905 (1999) 018. hep-th/9811168