124 research outputs found
BPS Electromagnetic Waves on Giant Gravitons
We find new 1/8-BPS giant graviton solutions in , carrying
three angular momenta along , and investigate their properties.
Especially, we show that nonzero worldvolume gauge fields are admitted
preserving supersymmetry. These gauge field modes can be viewed as
electromagnetic waves along the compact D3 brane, whose Poynting vector
contributes to the BPS angular momenta. We also analyze the (nearly-)spherical
giant gravitons with worldvolume gauge fields in detail. Expressing the
in Hopf fibration ( fibred over ), the wave propagates along the
fiber.Comment: 25 pages, no figures, v2: references adde
Electrified BPS Giants: BPS configurations on Giant Gravitons with Static Electric Field
We consider D3-brane action in the maximally supersymmetric type IIB
plane-wave background. Upon fixing the light-cone gauge, we obtain the
light-cone Hamiltonian which is manifestly supersymmetric. The 1/2 BPS
solutions of this theory (solutions which preserve 16 supercharges) are either
of the form of spherical three branes, the giant gravitons, or zero size point
like branes. We then construct specific classes of 1/4 BPS solutions of this
theory in which static electric field on the brane is turned on. These
solutions are deformations about either of the two 1/2 BPS solutions. In
particular, we study in some detail 1/4 BPS configurations with electric dipole
on the three sphere giant, i.e. BIons on the giant gravitons, which we hence
call BIGGons. We also study BPS configurations corresponding to turning on a
background uniform constant electric field. As a result of this background
electric field the three sphere giant is deformed to squashed sphere, while the
zero size point like branes turn into circular or straight fundamental strings
in the plane-wave background, with their tension equal to the background
electric field.Comment: 32 pages, 1 eps figure; v2: Presentation of derivation of light-cone
Hamiltonian improved, Refs adde
Dual giant gravitons in AdS Y (Sasaki-Einstein)
We consider BPS motion of dual giant gravitons on Ad where
represents a five-dimensional Sasaki-Einstein manifold. We find that the
phase space for the BPS dual giant gravitons is symplectically isomorphic to
the Calabi-Yau cone over , with the K\"{a}hler form identified with the
symplectic form. The quantization of the dual giants therefore coincides with
the K\"{a}hler quantization of the cone which leads to an explicit
correspondence between holomorphic wavefunctions of dual giants and
gauge-invariant operators of the boundary theory. We extend the discussion to
dual giants in where is a seven-dimensional
Sasaki-Einstein manifold; for special motions the phase space of the dual
giants is symplectically isomorphic to the eight-dimensional Calabi-Yau cone.Comment: 14 pages. (v2) typo's corrected; factors of AdS radius reinstated for
clarity; remarks about dual giant wavefunctions in T^{1,1} expanded and put
in a new subsectio
Half-BPS Giants, Free Fermions and Microstates of Superstars
We consider 1/2-BPS states in AdS/CFT. Using the matrix model description of
chiral primaries explicit mappings among configurations of fermions, giant
gravitons and the dual-giant gravitons are obtained. These maps lead to a
`duality' between the giant and the dual-giant configurations which is the
reflection of particle-hole duality of the fermion picture. These dualities
give rise to some interesting consequences which we study. We then calculate
the degeneracy of 1/2-BPS states both from the CFT and string theory and show
that they match. The asymptotic degeneracy grows exponentially with the
comformal dimension. We propose that the five-dimensional single charge
`superstar' geometry should carry this density of states. An appropriate
stretched horizon can be placed in this geometry and the entropy predicted by
the CFT and the string theory microstate counting can be reproduced by the
Bekenstein-Hawking formula up to a numerical coefficient. Similar M-theory
examples are also considered.Comment: 21 pages, v2:typos corrected and references adde
Counting 1/8-BPS Dual-Giants
We count 1/8-BPS states in type IIB string theory on AdS_5 x S^5 background
which carry three independent angular momenta on S^5. These states can be
counted by considering configurations of multiple dual-giant gravitons up to N
in number which share at least four supersymmetries. We map this counting
problem to that of counting the energy eigen states of a system of N bosons in
a 3-dimensional harmonic oscillator. We also count 1/8-BPS states with two
independent non-zero spins in AdS_5 and one non-zero angular momentum on S^5 by
considering configurations of arbitrary number of giant gravitons that share at
least four supersymmetries.Comment: 19 page
1/16-BPS Black Holes and Giant Gravitons in the AdS_5 X S^5 Space
We explore 1/16-BPS objects of type IIB string theory in AdS_5 * S^5. First,
we consider supersymmetric AdS_5 black holes, which should be 1/16-BPS and have
a characteristic that not all physical charges are independent. We point out
that the Bekenstein-Hawking entropy of these black holes admits a remarkably
simple expression in terms of (dependent) physical charges, which suggests its
microscopic origin via certain Cardy or Hardy-Ramanujan formula. We also note
that there is an upper bound for the angular momenta given by the electric
charges. Second, we construct a class of 1/16-BPS giant graviton solutions in
AdS_5 * S^5 and explore their properties. The solutions are given by the
intersections of AdS_5 * S^5 and complex 3 dimensional holomorphic hyperspaces
in C^{1+5}, the latter being the zero loci of three holomorphic functions which
are homogeneous with suitable weights on coordinates. We investigate examples
of giant gravitons, including their degenerations to tensionless strings.Comment: 25 pages, no figures, v2: references added, comments added in the
conclusio
Analysis of segregated boundary-domain integral equations for BVPs with non-smooth coefficients on Lipschitz domains
Segregated direct boundary-domain integral equations (BDIEs) based on a parametrix and associated with the Dirichlet and Neumann boundary value problems for the linear stationary diffusion partial differential equation with a variable Hölder-continuous coefficients on Lipschitz domains are formulated. The PDE right-hand sides belong to the Sobolev (Bessel potential) space Hsâ2(Ω ) or HËsâ2(Ω ) , 12<s<32, when neither strong classical nor weak canonical co-normal derivatives are well defined. Equivalence of the BDIEs to the original BVP, BDIE solvability, solution uniqueness/non-uniqueness, and the Fredholm property and invertibility of the BDIE operators are analysed in appropriate Sobolev spaces. It is shown that the BDIE operators for the Neumann BVP are not invertible; however, some finite-dimensional perturbations are constructed leading to invertibility of the perturbed (stabilised) operators.EPSR
Enhancement of Magneto-Optic Effects via Large Atomic Coherence
We utilize the generation of large atomic coherence to enhance the resonant
nonlinear magneto-optic effect by several orders of magnitude, thereby
eliminating power broadening and improving the fundamental signal-to-noise
ratio. A proof-of-principle experiment is carried out in a dense vapor of Rb
atoms. Detailed numerical calculations are in good agreement with the
experimental results. Applications such as optical magnetometry or the search
for violations of parity and time reversal symmetry are feasible
Entropy of near-extremal black holes in AdS_5
We construct the microstates of near-extremal black holes in AdS_5 x S^5 as
gases of defects distributed in heavy BPS operators in the dual SU(N)
Yang-Mills theory. These defects describe open strings on spherical D3-branes
in the S^5, and we show that they dominate the entropy by directly enumerating
them and comparing the results with a partition sum calculation. We display new
decoupling limits in which the field theory of the lightest open strings on the
D-branes becomes dual to a near-horizon region of the black hole geometry. In
the single-charge black hole we find evidence for an infrared duality between
SU(N) Yang-Mills theories that exchanges the rank of the gauge group with an
R-charge. In the two-charge case (where pairs of branes intersect on a line),
the decoupled geometry includes an AdS_3 factor with a two-dimensional CFT
dual. The degeneracy in this CFT accounts for the black hole entropy. In the
three-charge case (where triples of branes intersect at a point), the decoupled
geometry contains an AdS_2 factor. Below a certain critical mass, the
two-charge system displays solutions with naked timelike singularities even
though they do not violate a BPS bound. We suggest a string theoretic
resolution of these singularities.Comment: LaTeX; v2: references and a few additional comments adde
Observation of exclusive DVCS in polarized electron beam asymmetry measurements
We report the first results of the beam spin asymmetry measured in the
reaction e + p -> e + p + gamma at a beam energy of 4.25 GeV. A large asymmetry
with a sin(phi) modulation is observed, as predicted for the interference term
of Deeply Virtual Compton Scattering and the Bethe-Heitler process. The
amplitude of this modulation is alpha = 0.202 +/- 0.028. In leading-order and
leading-twist pQCD, the alpha is directly proportional to the imaginary part of
the DVCS amplitude.Comment: 6 pages, 5 figure
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