1,797 research outputs found

### D-branes in the diagonal SU(2) coset

The symmetry preserving D-branes in coset theories have previously been
described as being centered around projections of products of conjugacy classes
in the underlying Lie groups. Here, we investigate the coset where a diagonal
action of SU(2) is divided out from SU(2)\times SU(2). The corresponding target
space is described as a (3-dimensional) pillow with four distinguished corners.
It is shown that the (fractional) brane which corresponds to the fixed point
that arises in the CFT description, is spacefilling. Moreover, the spacefilling
brane is the only one that reaches all of the corners. The other branes are 3,
1 and 0 - dimensional.Comment: v2: reference added, 9 page

### The Conformal Limit of the 0A Matrix Model and String Theory on AdS(2)

We analyze the conformal limit of the matrix model describing flux
backgrounds of two dimensional type 0A string theory. This limit is believed to
be dual to an AdS(2) background of type 0A string theory. We show that the
spectrum of this limit is identical to that of a free fermion on AdS(2),
suggesting that there are no closed string excitations in this background.Comment: 17 pages, 1 figur

### Wrapped M2/M5 Duality

A microscopic accounting of the entropy of a generic 5D supersymmetric
rotating black hole, arising from wrapped M2-branes in Calabi-Yau compactified
M-theory, is an outstanding unsolved problem. In this paper we consider an
expansion around the zero-entropy, zero-temperature, maximally rotating ground
state for which the angular momentum J_L and graviphoton charge Q are related
by J_L^2=Q^3. At J_L=0 the near horizon geometry is AdS_2 x S^3. As J_L^2 goes
to Q^3 it becomes a singular quotient of AdS_3 x S^2: more precisely, a
quotient of the near horizon geometry of an M5 wrapped on a 4-cycle whose
self-intersection is the 2-cycle associated to the wrapped-M2 black hole. The
singularity of the AdS_3 quotient is identified as the usual one associated to
the zero-temperature limit, suggesting that the (0,4) wrapped-M5 CFT is dual
near maximality to the wrapped-M2 black hole. As evidence for this, the
microscopic (0,4) CFT entropy and the macroscopic rotating black hole entropy
are found to agree to leading order away from maximality.Comment: 10 pages, no figure

### New Reducible Five-brane Solutions in M-theory

We construct new M-theory solutions of M5 branes that are a realization of
the fully localized ten dimensional NS5/D6 and NS5/D5 brane intersections.
These solutions are obtained by embedding self-dual geometries lifted to
M-theory. We reduce these solutions down to ten dimensions, obtaining new
D-brane systems in type IIA/IIB supergravity. The worldvolume theories of the
NS5-branes are new non-local, non-gravitational, six dimensional, T-dual little
string theories with eight supersymmetries.Comment: 19 pages, 4 figures, two paragraphs added in conclusions, typos
correcte

### Counting Dyons in N=8 String Theory

A recently discovered relation between 4D and 5D black holes is used to
derive exact (weighted) BPS black hole degeneracies for 4D N=8 string theory
from the exactly known 5D degeneracies. A direct 4D microscopic derivation in
terms of weighted 4D D-brane bound state degeneracies is sketched and found to
agree.Comment: 10 page

### Superconformal Black Hole Quantum Mechanics

In recent work, the superconformal quantum mechanics describing D0 branes in
the AdS_2xS^2xCY_3 attractor geometry of a Calabi-Yau black hole with D4 brane
charges p^A has been constructed and found to contain a large degeneracy of
chiral primary bound states. In this paper it is shown that the asymptotic
growth of chiral primaries for N D0 branes exactly matches the
Bekenstein-Hawking area law for a black hole with D4 brane charge p^A and D0
brane charge N. This large degeneracy arises from D0 branes in lowest Landau
levels which tile the CY_3xS^2 horizon. It is conjectured that such a multi-D0
brane CFT1 is holographically dual to IIA string theory on AdS_2xS^2xCY_3.Comment: 8 page

### Entanglement Interpretation of Black Hole Entropy in String Theory

We show that the entropy resulting from the counting of microstates of non
extremal black holes using field theory duals of string theories can be
interpreted as arising from entanglement. The conditions for making such an
interpretation consistent are discussed. First, we interpret the entropy (and
thermodynamics) of spacetimes with non degenerate, bifurcating Killing horizons
as arising from entanglement. We use a path integral method to define the
Hartle-Hawking vacuum state in such spacetimes and discuss explicitly its
entangled nature and its relation to the geometry. If string theory on such
spacetimes has a field theory dual, then, in the low-energy, weak coupling
limit, the field theory state that is dual to the Hartle-Hawking state is a
thermofield double state. This allows the comparison of the entanglement
entropy with the entropy of the field theory dual, and thus, with the
Bekenstein-Hawking entropy of the black hole. As an example, we discuss in
detail the case of the five dimensional anti-de Sitter, black hole spacetime

### Brane Dynamics From the Born-Infeld Action

We use the abelian Born-Infeld action for the worldvolume gauge field and
transverse displacement scalars to explore new aspects of D-brane structure and
dynamics. We study several classic gauge field configurations, including point
charges in any worldvolume dimension and vortices in two worldvolume
dimensions, and show that, with an appropriate excitation of the transverse
coordinate field, they are BPS-saturated solutions. The Coulomb point charge
solutions turn out to represent, with considerable fidelity, fundamental
strings attached to the brane (their magnetic counterparts describe D1-branes
attached to D3-branes). We also show that S-matrix for small excitations
propagating on the point charge solution is consistent with (and gives further
illuminating information about) Polchinski's effective open string boundary
condition.Comment: 16 pages, 3 figures. Minor typos fixe

### M5-brane Effective Action as an On-shell Action in Supergravity

We show that the covariant effective action for M5-brane is a solution to the
Hamilton-Jacobi (H-J) equations of 11-dimensional supergravity. The solution to
the H-J equations reproduces the supergravity solution that represents the
M2-M5 bound states.Comment: 20 pages, references added, typos correcte

### Effective Actions for Massive Kaluza-Klein States on AdS_3 x S^3 x S^3

We construct the effective supergravity actions for the lowest massive
Kaluza-Klein states on the supersymmetric background AdS_3 x S^3 x S^3. In
particular, we describe the coupling of the supergravity multiplet to the
lowest massive spin-3/2 multiplet which contains 256 physical degrees of
freedom and includes the moduli of the theory. The effective theory is realized
as the broken phase of a particular gauging of the maximal three-dimensional
supergravity with gauge group SO(4) x SO(4). Its ground state breaks half of
the supersymmetries leading to 8 massive gravitinos acquiring mass in a super
Higgs effect. The holographic boundary theory realizes the large N=(4,4)
superconformal symmetry.Comment: 31 pages, v2: minor change

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