308 research outputs found
Notes on Branes in Matrix Theory
We study the effective actions of various brane configurations in Matrix
theory. Starting from the 0+1 dimensional quantum mechanics, we replace
coordinate matrices by covariant derivatives in the large N limit, thereby
obtaining effective field theories on the brane world volumes. Even for
noncompact branes, these effective theories are of Yang-Mills type, with
constant background magnetic fields. In the case of a D2-brane, we show
explicitly how the effective action equals the large magnetic field limit of
the Born-Infeld action, and thus derive from Matrix theory the action used by
Polchinski and Pouliot to compute M-momentum transfer between membranes. We
also consider the effect of compactifying transverse directions. Finally, we
analyze a scattering process involving a recently proposed background
representing a classically stable D6+D0 brane configuration. We compute the
potential between this configuration and a D0-brane, and show that the result
agrees with supergravity.Comment: 24 pages, LaTeX file. Minor typo correction
M-momentum Transfer between Gravitons, Membranes, and Fivebranes as Perturbative Gauge Theory Processes
Polchinski and Pouliot have shown that M-momentum transfer between membranes
in supergravity can be understood as a non-perturbative instanton effect in
gauge theory. Here we consider a dual process: electric flux transmission
between D-branes. We show that this process can be described in perturbation
theory as virtual string pair creation, and is closely related to Schwinger's
treatment of the pair creation of charged particles in a uniform electric
field. Through the application of dualities, our perturbative calculation gives
results for various non-perturbative amplitudes, including M-momentum transfer
between gravitons, membranes, and longitudinal fivebranes. Thus perturbation
theory plus dualities are sufficient to demonstrate agreement between
supergravity and gauge theory for a number of M-momentum transferring
processes. A variety of other processes where branes are transmitted between
branes, e.g. (p,q)-string transmission in IIB-theory, can also be studied. We
discuss the implications of our results for proving the 11 dimensional Lorentz
invariance of Matrix theory.Comment: 16 pages, LaTeX, 1 Postscript figure, uses epsf.tex and fps.sty
macro
Quantum Hall Effect in AdS/CFT
Drawing on the connection with superconductivity, we give a simple AdS
realization of the quantum Hall effect. The theory includes a statistical gauge
field with a Chern-Simons term, in analogy with effective field theory models
of the QHE.Comment: 12 page
Resolving the black hole information paradox
The recent progress in string theory strongly suggests that formation and
evaporation of black holes is a unitary process. This fact makes it imperative
that we find a flaw in the semiclassical reasoning that implies a loss of
information. We propose a new criterion that limits the domain of classical
gravity: the hypersurfaces of a foliation cannot be stretched too much. This
conjectured criterion may have important consequences for the early Universe.Comment: harvmac, 11 pages (1 figure) (This essay received an ``honorable
mention'' in the Annual Essay Competition of the Gravity Research Foundation
for the year 2000.
The Ground State Structure and Modular Transformations of Fractional Quantum Hall States on a Torus
The structure of ground states of generic FQH states on a torus is studied by
using both effective theory and electron wave function. The relation between
the effective theory and the wave function becomes transparent when one
considers the ground state structure. We find that the non-abelian Berry's
phases of the abelian Hall states generated by twisting the mass matrix are
identical to the modular transformation matrix for the characters of a Gaussian
conformal field theory. We also show that the Haldane-Rezayi spin singlet state
has a ten fold degeneracy on a torus which indicates such a state is a
non-abelian Hall state.Comment: 28 pages, LATEX, 9 figures available by request from authors,
CTP-2197 (two references added + some minor typos corrected
Electrostatics approach to closed string pair production from a decaying D-brane
We consider the emission of two closed string tachyons from a decaying
Dp-brane in bosonic string theory. We study the high energy limit of the
emission amplitude by using an analogue to electrostatics. The case where the
emitted strings have equal energies is analyzed in detail, and we obtain a
relatively simple result for the emission amplitude. We identify expected poles
for s- and t-channel emission. In the high energy limit, the amplitude decays
exponentially (~e^{-2\pi\omega}) or faster in the energies \omega of the closed
strings.Comment: 28 pages, 2 figure
Timelike Boundary Sine-Gordon Theory and Two-Component Plasma
It has long been known that there is a relation between boundary sine-Gordon
theory and thermodynamics of charge neutral two-component Coulomb plasma on a
unit circle. On the other hand, recently it was found that open string
worldsheet description of brane decay can be related to a sequence of points of
thermodynamic equilibrium of one-component plasma. Here we consider a different
decay process which is specifically described by the timelike boundary
sine-Gordon theory. We find time evolution to be mapped to a one-dimensional
curve in the space of points of thermal equilibrium of a non-neutral
two-component Coulomb plasma. We compute the free energy of the system and find
that along the curve it is monotonously decreasing, defining a thermodynamic
arrow of time.Comment: 11 pages, v2: reference adde
- …