Various aspects of branes in the recently proposed matrix model for M theory are discussed. A careful analysis of the supersymmetry algebra of the matrix model uncovers some central charges which can… (More)

Tom Banks , Michael R. Douglas , Gary T. Horowitz , and Emil Martinec †d † Institute for Theoretical Physics Santa Barbara, CA 93106-4030 ∗ Department of Physics and Astronomy Rutgers University,… (More)

We show that a subgroup of the modular group of M-theory compactified on a ten torus, implies the Lorentzian structure of the moduli space, that is usually associated with naive discussions of… (More)

If nature is described by string theory, and if the compactification radius is large (as suggested by the unification of couplings), then the theory is in a regime best described by the low energy… (More)

We study the symmetry structure of N = 8 quantum mechanics, and apply it to the physics of D0-brane probes in type I’ string theory. We focus on the theory with a global Spin(8) R symmetry which… (More)

There has been some debate as to whether the landscape does or does not predict low energy supersymmetry. We argue that under rather mild assumptions, the landscape seems to favor such breaking,… (More)

The decay constant of the QCD axion is required by observation to be small compared to the Planck scale. In theories of “natural inflation,” and certain proposed anthropic solutions of the… (More)

The force between like sign BPS saturated objects generally vanishes. This is a reflection of the fact that BPS states are really massless uncharged particles with nonvanishing momenta in… (More)

We present a new cosmological model, based on the holographic principle, which shares many of the virtues of inflation. The very earliest semiclassical era of the universe is dominated by a dense gas… (More)

It is natural to ask whether non-commutative geometry plays a role in four dimensional physics. By performing explicit computations in various toy models, we show that quantum effects lead to… (More)