344 research outputs found
The M5-Brane Elliptic Genus: Modularity and BPS States
The modified elliptic genus for an M5-brane wrapped on a four-cycle of a
Calabi-Yau threefold encodes the degeneracies of an infinite set of BPS states
in four dimensions. By holomorphy and modular invariance, it can be determined
completely from the knowledge of a finite set of such BPS states. We show the
feasibility of such a computation and determine the exact modified elliptic
genus for an M5-brane wrapping a hyperplane section of the quintic threefold.Comment: 21 page
Examples of M5-Brane Elliptic Genera
We determine the modified elliptic genus of an M5-brane wrapped on various
one modulus Calabi-Yau spaces, using modular invariance together with some
known Gopakumar-Vafa invariants of small degrees. As a bonus, we find
nontrivial relations among Gopakumar-Vafa invariants of different degrees and
genera from modular invariance.Comment: 13 page
Expectation values of chiral primary operators in holographic interface CFT
We consider the expectation values of chiral primary operators in the
presence of the interface in the 4 dimensional N=4 super Yang-Mills theory.
This interface is derived from D3-D5 system in type IIB string theory. These
expectation values are computed classically in the gauge theory side. On the
other hand, this interface is a holographic dual to type IIB string theory on
AdS_5 x S^5 spacetime with a probe D5-brane. The expectation values are
computed by GKPW prescription in the gravity side. We find non-trivial
agreement of these two results: the gauge theory side and the gravity side.Comment: 17pages, no figur
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
Supersymmetric D-branes in the D1-D5 background
We construct supersymmetric D-brane probe solutions in the background of the
2-charge D1-D5 system on M, where M is either K3 or T^4. We focus on
`near-horizon bound states' that preserve supersymmetries of the near-horizon
AdS_3 x S^3 x M geometry and are static with respect to the global time
coordinate. We find a variety of half-BPS solutions that span an AdS_2 subspace
in AdS_3, carry worldvolume flux and can wrap an S^2 within S^3 and/or
supersymmetric cycles in M.Comment: Latex, 24 pages. v2: references added, modified Discussion, published
versio
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
The elliptic genus from split flows and Donaldson-Thomas invariants
We analyze a mixed ensemble of low charge D4-D2-D0 brane states on the
quintic and show that these can be successfully enumerated using attractor flow
tree techniques and Donaldson-Thomas invariants. In this low charge regime one
needs to take into account worldsheet instanton corrections to the central
charges, which is accomplished by making use of mirror symmetry. All the
charges considered can be realized as fluxed D6-D2-D0 and anti-D6-D2-D0 pairs
which we enumerate using DT invariants. Our procedure uses the low charge
counterpart of the picture developed Denef and Moore. By establishing the
existence of flow trees numerically and refining the index factorization
scheme, we reproduce and improve some results obtained by Gaiotto, Strominger
and Yin. Our results provide appealing evidence that the strong split flow tree
conjecture holds and allows to compute exact results for an important sector of
the theory. Our refined scheme for computing indices might shed some light on
how to improve index computations for systems with larger charges.Comment: 37 pages, 12 figure
c=1 Matrix Models: Equivalences and Open-Closed String Duality
We give an explicit demonstration of the equivalence between the Normal
Matrix Model (NMM) of c=1 string theory at selfdual radius and the
Kontsevich-Penner (KP) model for the same string theory. We relate macroscopic
loop expectation values in the NMM to condensates of the closed string tachyon,
and discuss the implications for open-closed duality. As in c<1, the
Kontsevich-Miwa transform between the parameters of the two theories appears to
encode open-closed string duality, though our results also exhibit some
interesting differences with the c<1 case. We also briefly comment on two
different ways in which the Kontsevich model originates.Comment: 27 pages, latex, 1 figure, typos, discussion added, acknowledgements
update
Noncritical String Correlators, Finite-N Matrix Models and the Vortex Condensate
We carry out a systematic study of correlation functions of momentum modes in
the Euclidean c=1 string, as a function of the radius and to all orders in
perturbation theory. We obtain simple explicit expressions for several classes
of correlators in terms of special functions. The Normal Matrix Model is found
to be a powerful calculational tool that computes c=1 string correlators even
at finite N. This enables us to obtain a simple combinatoric formula for the
2n-point function of unit momentum modes, which after T-duality determines the
vortex condensate. We comment on possible applications of our results to
T-duality at c=1 and to the 2d black hole/vortex condensate problem.Comment: 38 pages, LaTe
Note on Generalized Janus Configurations
We study several aspects of generalized Janus configuration, which includes a
theta term. We investigate the vacuum structure of the theory and find that
unlike the Janus configuration without theta term there is no nontrivial
vacuum. We also discuss BPS soliton configuration both by supersymmetry
analysis and from energy functional. The half BPS configurations could be
realized by introducing transverse (p,q)-strings in original brane
configuration corresponding to generalized Janus configuration. It turns out
the BPS soliton could be taken as modified dyon. We discuss the solution of
half BPS equations for the sharp interface case. Moreover we construct less
supersymmetric Janus configuration with theta term.Comment: 27 pages; References adde
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