137 research outputs found
String solitons in the M5-brane worldvolume with a Nambu-Poisson structure and Seiberg-Witten map
We analyze BPS equations for string-like configurations derived from the
M5-brane worldvolume action with a Nambu-Poisson structure constructed in
arXiv:0804.3629, arXiv:0805.2898. We solve the BPS equations up to the first
order in the parameter which characterizes the strength of the
Nambu-Poisson bracket. We compare our solutions to previously constructed BPS
string solitons in the conventional description of M5-brane in a constant
three-form background via Seiberg-Witten map, and find agreement.Comment: v2: minor corrections, the title slightly changed. 10 pages. v3: some
clarifying comment
Calculating the Prepotential by Localization on the Moduli Space of Instantons
We describe a new technique for calculating instanton effects in
supersymmetric gauge theories applicable on the Higgs or Coulomb branches. In
these situations the instantons are constrained and a potential is generated on
the instanton moduli space. Due to existence of a nilpotent fermionic symmetry
the resulting integral over the instanton moduli space localizes on the
critical points of the potential. Using this technology we calculate the one-
and two-instanton contributions to the prepotential of SU(N) gauge theory with
N=2 supersymmetry and show how the localization approach yields the prediction
extracted from the Seiberg-Witten curve. The technique appears to extend to
arbitrary instanton number in a tractable way.Comment: 24 pages, JHEP.cls, more references and extra discussion on N_F=2N
cas
Large N Reductions and Holography
The large reductions in gauge theories are identified with dimensional
reductions with homogeneous distribution of the eigenvalues of the gauge field,
and it is used to identify the corresponding closed string descriptions in the
Maldacena duality. When one does not take the zero-radii limit, the large
reductions are naturally extended to the equivalences between the gauge
theories and the "generalized" reduced models, which naturally contain the
notion of T-dual equivalence. In the dual gravitational description, T-duality
relates two type IIB supergravity solutions, the near horizon geometry of
D3-branes, and the near horizon geometry of D-instantons densely and
homogeneously distributing on the dual torus. This is the holographic
description of the generalized large reductions. A new technique for
calculating correlation functions of local gauge invariant single trace
operators from the reduced models is also given.Comment: REVTeX4 v2: simple mistake in eq.(1) corrected. footnote 4 in v1
expanded in the main body. conflicting notations for the dilaton below eq.(6)
(in v1) fixed. 6 pages, 5 figures v3: corrected typo v4: presentation
improved with explanations and clarifications. results unchanged. refs added.
8page
Non-Commutative Instantons and the Seiberg-Witten Map
We present several results concerning non-commutative instantons and the
Seiberg-Witten map. Using a simple ansatz we find a large new class of
instanton solutions in arbitrary even dimensional non-commutative Yang-Mills
theory. These include the two dimensional ``shift operator'' solutions and the
four dimensional Nekrasov-Schwarz instantons as special cases. We also study
how the Seiberg-Witten map acts on these instanton solutions. The infinitesimal
Seiberg-Witten map is shown to take a very simple form in operator language,
and this result is used to give a commutative description of non-commutative
instantons. The instanton is found to be singular in commutative variables.Comment: 26 pages, AMS-LaTeX. v2: the formula for the commutative description
of the Nekrasov-Schwarz instanton corrected (sec. 4). v3: minor correction
More on the Nambu-Poisson M5-brane Theory: Scaling limit, background independence and an all order solution to the Seiberg-Witten map
We continue our investigation on the Nambu-Poisson description of M5-brane in
a large constant C-field background (NP M5-brane theory) constructed in
Refs.[1, 2]. In this paper, the low energy limit where the NP M5-brane theory
is applicable is clarified. The background independence of the NP M5-brane
theory is made manifest using the variables in the BLG model of multiple
M2-branes. An all order solution to the Seiberg-Witten map is also constructed.Comment: expanded explanations, minor corrections and typos correcte
The flux of noncommutative U(1) instanton through the fuzzy spheres
From the ADHM construction on noncommutative we investigate
different U(1) instanton solutions tied by isometry trasformations. These
solutions present a form of vector fields in noncommutative
vector space which makes possible the calculus of their fluxes through fuzzy
spheres. We establish the noncommutative analog of Gauss theorem from which we
show that the flux of the U(1) instantons through fuzzy spheres does not depend
on the radius of these spheres and it is invariant under isometry
transformations.Comment: 18 pages, new version to appear in Int. Jour. of Mod. Phys.
From Free Fields to AdS -- Thermal Case
We analyze the reorganization of free field theory correlators to closed
string amplitudes investigated in hep-th/0308184 hep-th/0402063 hep-th/0409233
hep-th/0504229 in the case of Euclidean thermal field theory and study how the
dual bulk geometry is encoded on them. The expectation value of Polyakov loop,
which is an order parameter for confinement-deconfinement transition, is
directly reflected on the dual bulk geometry. The dual geometry of confined
phase is found to be AdS space periodically identified in Euclidean time
direction. The gluing of Schwinger parameters, which is a key step for the
reorganization of field theory correlators, works in the same way as in the
non-thermal case. In deconfined phase the gluing is made possible only by
taking the dual geometry correctly. The dual geometry for deconfined phase does
not have a non-contractible circle in the Euclidean time direction.Comment: LaTeX, 1+31 pages, 8 figures v2: refs corrected v3: minor corrections
v4: to match with published versio
Quasi-localized states on noncommutative solitons
We consider noncommutative gauge theories which have zero mass states
propagating along both commutative and noncommutative dimensions. Solitons in
these theories generically carry U(m) gauge group on their world-volume. From
the point of view of string theory, these solitons correspond to
``branes within branes''. We show that once the world-volume U(m) gauge
theory is in the Higgs phase, light states become quasi-localized, rather than
strictly localized on the soliton, i.e. they mix with light bulk modes and have
finite widths to escape into the noncommutative dimensions. At small values of
U(m) symmetry breaking parameters, these widths are small compared to the
corresponding masses. Explicit examples considered are adjoint scalar field in
the background of a noncommutative vortex in U(1)-Higgs theory, and gauge
fields in instanton backgrounds in pure gauge noncommutative theories.Comment: 27 pages, references and comments added, final version to appear in
JHE
Affleck-Dine baryogenesis in inflating curvaton scenario with O(TeV) mass moduli curvaton
We study the Affleck-Dine (AD) baryogenesis in the inflating curvaton
scenario, when the curvaton is a moduli field with O(TeV) mass. A
moduli field with such mass is known to be free from the Polonyi problem, and
furthermore its decay products can explain the present cold dark matter
abundance. In our scenario, it further explains the primordial curvature
perturbation and the present baryon density all together. The current
observational bound on the baryon isocurvature perturbation, which severely
constrains the AD baryogenesis with the original oscillating moduli curvaton
scenario, is shown to put practically negligible constraint if we replace the
oscillating curvaton with the inflating curvaton.Comment: 1+21pages v2: minor correction v3: included short reviews, added
refs, fixed typo
Noncommutative Moduli for Multi-Instantons
There exists a recursive algorithm for constructing BPST-type
multi-instantons on commutative R^4. When deformed noncommutatively, however,
it becomes difficult to write down non-singular instanton configurations with
topological charge greater than one in explicit form. We circumvent this
difficulty by allowing for the translational instanton moduli to become
noncommutative as well. This makes possible the ADHM construction of 't Hooft
multi-instanton solutions with everywhere self-dual field strengths on
noncommutative R^4.Comment: 1+9 pages; v2: reference added, published versio
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