1,401 research outputs found
Deconstructing Supersymmetric S-matrices in D <= 2 + 1
Global supersymmetries of the S-matrices of N = 2, 4, 8 supersymmetric
Yang-Mills theories in three spacetime dimensions (without matter
hypermultiplets) are shown to be SU(1|1), SU(2|2) and SU(2|2) X SU(2|2)
respectively. These symmetries are not manifest in the off-shell Lagrangian
formulations of these theories. A direct map between these symmetries and their
representations in terms of the Yang-Mills degrees of freedom and the
corresponding quantities in Chern-Simons-Matter theories with N >= 4
supersymmetry is also obtained. Dimensional reduction of the on-shell
observables of the Yang-Mills theories to two spacetime dimensions is also
discussed.Comment: 1+13 page
Wilson Loops in N=2 Superconformal Yang-Mills Theory
We present a three-loop O(g^6) calculation of the difference between the
expectation values of Wilson loops evaluated in N=4 and superconformal N=2
supersymmetric Yang-Mills theory with gauge group SU(N) using dimensional
reduction. We find a massive reduction of required Feynman diagrams, leaving
only certain two-matter-loop corrections to the gauge field and associated
scalar propagator. This "diagrammatic difference" leaves a finite result
proportional to the bare propagators and allows the recovery of the zeta(3)
term coming from the matrix model for the 1/2 BPS circular Wilson loop in the
N=2 theory. The result is valid also for closed Wilson loops of general shape.
Comments are made concerning light-like polygons and supersymmetric loops in
the plane and on S^2.Comment: 16 pages. v2 minor changes, to appear in JHEP. v3 corrected
reference
Wilson loops in 3-dimensional N=6 supersymmetric Chern-Simons Theory and their string theory duals
We study Wilson loops in the three-dimensional N=6 supersymmetric
Chern-Simons theory recently constructed by Aharony, Bergman, Jafferis and
Maldacena, that is conjectured to be dual to type IIA string theory on AdS_4 x
CP^3. We construct loop operators in the Chern-Simons theory which preserve 1/6
of the supercharges and calculate their expectation value up to 2-loop order at
weak coupling. The expectation value at strong coupling is found by
constructing the string theory duals of these operators. For low dimensional
representations these are fundamental strings, for high dimensional
representations these are D2-branes and D6-branes. In support of this
identification we demonstrate that these string theory solutions match the
symmetries, charges and the preserved supersymmetries of their Chern-Simons
theory counterparts.Comment: 28 pages. v2: references added, choice of the Wilson loop operator
clarified; v3: combinatorial factor of 2 in perturbative calculation
corrected; v4: typos corrected, version to be publishe
On the Regularization of Extremal Three-point Functions Involving Giant Gravitons
In the AdS_5/CFT_4 set-up, extremal three-point functions involving two giant
1/2 BPS gravitons and one point-like 1/2 BPS graviton, when calculated using
semi-classical string theory methods, match the corresponding three-point
functions obtained in the tree-level gauge theory. The string theory
computation relies on a certain regularization procedure whose justification is
based on the match between gauge and string theory. We revisit the
regularization procedure and reformulate it in a way which allows a
generalization to the ABJM set-up where three-point functions of 1/2 BPS
operators are not protected and where a match between tree-level gauge theory
and semi-classical string theory is hence not expected.Comment: 5 pages, no figures. v2 updated reference
Counting Bubbles in Linear Chord Diagrams
In a linear chord diagram a short chord is one which joins adjacent vertices.
We define a bubble to be a region in a linear chord diagram devoid of short
chords. We derive a formal generating function counting bubbles by their size
and find an exact result for the mean bubble size. We find that once one
discards diagrams which have no short chords at all, the distribution of bubble
sizes is given by a smooth function in the limit of long diagrams. Using a
summation over short chords, the exact form of this asymptotic distribution is
found.Comment: 9 pages, 3 figure
To Dream The Old Dreams For Me
https://digitalcommons.library.umaine.edu/mmb-vp/6509/thumbnail.jp
Free Energy and Phase Transition of the Matrix Model on a Plane-Wave
It has recently been observed that the weakly coupled plane wave matrix model
has a density of states which grows exponentially at high energy. This implies
that the model has a phase transition. The transition appears to be of first
order. However, its exact nature is sensitive to interactions. In this paper,
we analyze the effect of interactions by computing the relevant parts of the
effective potential for the Polyakov loop operator in the finite temperature
plane-wave matrix model to three loop order. We show that the phase transition
is indeed of first order. We also compute the correction to the Hagedorn
temperature to order two loops.Comment: 24 page
- …