Gravitating M(atrix) Q-Balls

We suggest and motivate a precise equivalence between uncompactified eleven dimensional M-theory and the N = infinity limit of the supersymmetric matrix quantum mechanics describing D0-branes. The evidence for the conjecture consists of several correspondences between the two theories. As a consequence of supersymmetry the simple matrix model is rich enough to describe the properties of the entire Fock space of massless well separated particles of the supergravity theory. In ...

We investigate a bunch of D0-branes to reveal its quantum nature from the gravity side. In the classical limit, it is well described by a non-extremal black 0-brane in type IIA supergravity. The solution is uplifted to the eleven dimensions and expressed by a non-extremal M-wave solution. After reviewing the effective action for the M-theory, we explicitly solve the equations of motion for the near horizon geometry of the M-wave. As a result we derive an unique solution which...

Using Matrix theory, we propose a technique on how to compute the entangle- ment entropy between a supergravity probe and modes on a spherical membrane. We demonstrate that a membrane stretched between the probe and the sphere entangles these modes and can lead to an the entanglement entropy that encodes information about local gravitational geometry seen by the probe.

BMN Matrix theory admits vacua in the shape of large spherical membranes. Per- turbing around such vacua, the setup provides for a controlled computational frame- work for testing information evolution in Matrix black holes. The theory realizes excitations in the supergravity multiplet as qubits. These qubits are coupled to matrix degrees of freedom that describe deformations of the spherical shape of the membrane. Arranging the ripples on the membrane into a heat bath, we us...

We present a construction in Matrix theory of longitudinal 5-branes whose geometry in transverse space corresponds to a 4-sphere. We describe these branes through an explicit construction in terms of N*N matrices for a particular infinite series of values of N. The matrices used in the construction have a number of properties which can be interpreted in terms of the 4-sphere geometry, in analogy with similar properties of the SU(2) generators used in the construction of a sph...

We propose a large $N$ quantum mechanics of non-abelian bosonic and fermionic variables as a model for quantum gravity. The theory admits fuzzy sphere as static solution. Over the fuzzy geometry, the quantum mechanics of the fermions is given by a sum of oscillators with equal frequency. The energy state where exactly half of the Fermi sea is filled contains the maximal amount of degeneracy. This state of the fuzzy sphere obeys the mass-radius relation of a Schwarzschild blac...

We examine five dimensional extreme black holes with three charges in the matrix model. We build configurations of the 5+1 super Yang-Mills theory which correspond to black holes with transverse momentum charge. We calculate their mass and entropy from the super Yang-Mills theory and find that they match the semi-classical black hole results. We extend our results to nonextreme black holes in the dilute gas approximation.

I discuss the relation between M-theory and M(atrix)-theory in flat space by considering the effective potential for the scattering of two groups of D0-branes in both theories. An explicit calculation of this potential up to two loop order in M(atrix)-theory reveals a fascinating agreement. Lecture given at Strings '97; June 17, 1997.

Recently, in collaboration with Susskind, we proposed a model of Schwarzschild black holes in Matrix theory. A large Schwarzschild black hole is described by a metastable bound state of a large number of D0-branes which are held together by a background, whose structure has so far been understood only in 8 and 11 dimensions. The Hawking radiation proceeds by emission of small clusters of D0-branes. We estimate the Hawking rate in the Matrix theory model of Schwarzschild black...

The issue of justifying the matrix-theory proposal is revisited. We first discuss how the matrix-string theory is derived directly starting from the eleven dimensional supermembrane wrapped around a circle of radius $R=g_s\ell_s$, without invoking any stringy assumptions, such as S- and T-dualities. This derivation provides us a basis for studying both string ($R\to 0)$- and M ($R\to \infty$)-theory limits of quantum membrane theory in a single unified framework. In particula...