50 research outputs found
Nearing Extremal Intersecting Giants and New Decoupled Sectors in N = 4 SYM
We study near-horizon limits of near-extremal charged black hole solutions to
five-dimensional gauged supergravity carrying two charges, extending
the recent work of Balasubramanian et.al. We show that there are two
near-horizon decoupling limits for the near-extremal black holes, one
corresponding to the near-BPS case and the other for the far from BPS case.
Both of these limits are only defined on the 10d IIB uplift of the 5d black
holes, resulting in a decoupled geometry with a six-dimensional part (conformal
to) a rotating BTZ X . We study various aspects of these decoupling limits
both from the gravity side and the dual field theory side. For the latter we
argue that there should be two different, but equivalent, dual gauge theory
descriptions, one in terms of the 2d CFT's dual to the rotating BTZ and the
other as certain large R-charge sectors of d=4,N =4 U(N) SYM theory. We discuss
new BMN-type sectors of the N=4 SYM in the limit in which the
engineering dimensions scale as (for the near-BPS case) and as
(for the far from BPS case).Comment: 44 pages, references added, minor change
On Isolated Conformal Fixed Points and Noncritical String Theory
We search for the gravity description of unidentified field theories at their
conformal fixed points by studying the low energy effective action of six
dimensional noncritical string theory. We find constant dilaton solutions by
solving both the equations of motion and BPS equations. Our solutions include a
free parameter provided by a stack of uncharged space filling branes. We find
several AdS_p\times S^q solutions with constant radii for AdS_p and S^q. The
curvature of the solutions are of the order of the string scale.Comment: 17 pages, Latex fil
Circular Semiclassical String solutions on Confining AdS/CFT Backgrounds
We study multiwrapped circular string pulsating in the radial direction of
AdS black hole. We compute the energy of this string as a function of a large
quantum number n. One then could associate it with energy and a quantum number
of states in the dual finite temperature {\cal N}=4 SYM theory as well as three
dimensional pure gauge theory. We observe that the n dependence of the energy
has a universal form. We have also considered pulsating string in the
background of the near-extremal D4-brane solution. Circular pulsating membrane
in M-theory on AdS_7\times S^4 has also been studied.Comment: 14 pages, latex, v2: typos corrected, refs. adde
2D Gravity on with Chern-Simons Corrections
We study 2D Maxwell-dilaton gravity with higher order corrections given by
the Chern-Simons term. The model admits three distinctive vacuum
solutions. By making use of the entropy function formalism we find the entropy
of the solutions which is corrected due to the presence of the Chern-Simons
term. We observe that the form of the correction depends not only on the
coefficient of the Chern-Simons term, but also on the sign of the electric
charge; pointing toward the chiral nature of the dual CFT. Using the asymptotic
symmetry of the theory as well as requiring a consistent picture we can find
the central charge and the level of U(1) current. Upon uplifting the solutions
to three dimensions we get purely geometric solutions which will be either
or warped with an identification.Comment: 15 pages; V2: refs adde
Holographic Phase Transition to Topological Dyons
The dynamical stability of a Julia-Zee solution in the AdS background in a
four dimensional Einstein-Yang-Mills-Higgs theory is studied. We find that the
model with a vanishing scalar field develops a non-zero value for the field at
a certain critical temperature which corresponds to a topological dyon in the
bulk and a topological phase transition at the boundary.Comment: 18 pages, 2 figures, 2 tables, sections 2 and 4 are shortened, an
error in the last part of section 5 is corrected and equations are modified.
This version to be published in JHE
Semiclassical String Solutions on deformed NS5-brane Backgrounds and New Plane wave
We study different Penrose limits of supergravity solution of NS5-brane in
the presence of RR field. Although in the case of NS5-brane we get a
4-dimensional plane wave, in the case with RR field we will get two different
plane waves; a 4-dimensional and a 3-dimensional one. These plane wave
solutions are the backgrounds that a particular string solution feels at one
loop approximation. Using the one loop correction one can identify a particular
subsector of LST/deformed LST which is dual to type II string theories on these
plane waves.Comment: 18 pages, latex, v2: Minor changes, typos correcte
Dual Spikes; New Spiky String Solutions
We find a new class of spiky solutions for closed strings in flat,
and backgrounds. In the flat
case the new solutions turn out to be T-dual configurations of spiky strings
found by Kruczenski hep-th/0410226. In the case of solutions living in ,
we make a semi classical analysis by taking the large angular momentum limit.
The anomalous dimension for these dual spikes is similar to that for rotating
and pulsating circular strings in AdS with angular momentum playing the role of
the level number. This replaces the well known logarithmic dependence for
spinning strings. For the dual spikes living on sphere we find that no large
angular momentum limit exists.Comment: Added reference
On Effective Superpotentials and Compactification to Three Dimensions
We study four dimensional N=2 SO/SP supersymmetric gauge theory on R^3\times
S^1 deformed by a tree level superpotential. We will show that the exact
superpotential can be obtained by making use of the Lax matrix of the
corresponding integrable model which is the periodic Toda lattice. The
connection between vacua of SO(2N) and SO(2kN-2k+2) can also be seen in this
framework. Similar analysis can also be applied for SO(2N+1) and SP(2N).Comment: 18 pages, latex file, v2: typos corrected, refs adde
N=1 G_2 SYM theory and Compactification to Three Dimensions
We study four dimensional N=2 G_2 supersymmetric gauge theory on R^3\times
S^1 deformed by a tree level superpotential. We will show that the exact
superpotential can be obtained by making use of the Lax matrix of the
corresponding integrable model which is the periodic Toda lattice based on the
dual of the affine G_2 Lie algebra. At extrema of the superpotential the
Seiberg-Witten curve typically factorizes, and we study the algebraic equations
underlying this factorization. For U(N) theories the factorization was closely
related to the geometrical engineering of such gauge theories and to matrix
model descriptions, but here we will find that the geometrical interpretation
is more mysterious. Along the way we give a method to compute the gauge theory
resolvent and a suitable set of one-forms on the Seiberg-Witten curve. We will
also find evidence that the low-energy dynamics of G_2 gauge theories can
effectively be described in terms of an auxiliary hyperelliptic curve.Comment: 27 pages, late
Conformal SO(2,4) Transformations for the Helical AdS String Solution
By applying the conformal SO(2,4) transformations to the folded rotating
string configuration with two spins given by a certain limit from the helical
string solution in AdS_3 x S^1, we construct new string solutions whose
energy-spin relations are characterized by the boost parameter. When two
SO(2,4) transformations are performed with two boost parameters suitably
chosen, the straight folded rotating string solution with one spin in AdS_3 is
transformed in the long string limit into the long spiky string solution whose
expression is given from the helical string solution in AdS_3 by making a limit
that the modulus parameter becomes unity.Comment: 16 pages, LaTex, no figure