arXiv subjects

Steven Corley

Publications and source records attributed to Steven Corley.

13 recordsLinked to original sources

arXiv2003

Notes on anomalies, baryons, and Seiberg duality

We consider an N=1 SU(N_c) SUSY gauge theory with N_f \geq N_c matter multiplets transforming in the fundamental and antifundamental representations of the gauge group. Using the Konishi anomaly and a non-anomalous conservation law, we derive a system of partial differential equations that determine the low energy effective superpotential as a function of the mesonic and baryonic vacuum expectation values. We apply the formalism to the cases of N_f = N_c and N_f = N_c +1 where the equations are easily integrated and recover the known results. We further apply the formalism to derive a system of partial differential equations to determine the low energy effective superpotential for the Seiberg dual theories. Finally we briefly discuss the associated matrix models via the Dijkgraaf-Vafa conjecture.

hep-th↗

arXiv2002

Probing the Enhancon via Calculations in Supersymmetric Gauge Theory

We consider the N=2 gauge theory on N D7-branes wrapping K3, with D3-brane probes. In the large N limit, the D7-branes blow up to form an enhancon shell. We probe the region inside and outside the enhancon shell using the D3-branes, and compute the probe metric using the Seiberg-Witten formalism. Supergravity arguments suggest a flat interior up to 1/N corrections, and indeed our results for the D3-brane probes are consistent with that. By including the dynamics of the branes, these results, together with those of hep-th/0204050, demonstrate the robustness of the enhancon mechanism beyond patching together of supergravity solutions with D-brane source junction conditions.

hep-th↗

arXiv2002

Finite Factorization equations and Sum Rules for BPS correlators in N=4 SYM theory

A class of exact non-renormalized extremal correlators of half-BPS operators in N=4 SYM, with U(N) gauge group, is shown to satisfy finite factorization equations reminiscent of topological gauge theories. The finite factorization equations can be generalized, beyond the extremal case, to a class of correlators involving observables with a simple pattern of SO(6) charges. The simple group theoretic form of the correlators allows equalities between ratios of correlators in N=4 SYM and Wilson loops in Chern-Simons theories at k=\infty, correlators of appropriate observables in topological G/G models and Wilson loops in two-dimensional Yang-Mills theories. The correlators also obey sum rules which can be generalized to off-extremal correlators. The simplest sum rules can be viewed as large k limits of the Verlinde formula using the Chern-Simons correspondence. For special classes of correlators, the saturation of the factorization equations by a small subset of the operators in the large N theory is related to the emergence of semiclassical objects like KK modes and giant gravitons in the dual ADS \times S background. We comment on an intriguing symmetry between KK modes and giant gravitons.

hep-th↗

arXiv2002

Moduli Space Metric of N=2 Supersymmetric SU(N) Gauge Theory and the Enhancon

We compute the moduli space metric of SU(N) Yang-Mills theory with N=2 supersymmetry in the vicinity of the point where the classical moduli vanish. This gauge theory may be realized as a set of N D7-branes wrapping a K3 surface, near the enhancon locus. The moduli space metric determines the low-energy worldvolume dynamics of the D7 branes near this point, including stringy corrections. Non-abelian gauge symmetry is not restored on the worldvolume at the enhancon point, but rather the gauge group remains U(1)^{N-1} and light electric and magnetically charged particles coexist. We also study the moduli space metric for a single probe brane in the background of N-1 branes near the enhancon point. We find quantum corrections to the supergravity probe metric that are not suppressed at large separations, but are down by 1/N factors, due to the response of the N-1 enhancon branes to the probe. A singularity appears before the probe reaches the enhancon point where a dyon becomes massless. We compute the masses of W-bosons and monopoles in a large N limit near this critical point.

hep-th↗

arXiv2001

Forces between stable non-BPS branes

As a step toward constructing realistic brane world models in string theory, we consider the interactions of a pair of non-BPS branes. We construct a dyonic generalization of the non-BPS branes first constructed by Bergman, Gaberdiel and Sen as orbifolds of D-branes on $T^4/\BZ_2$. The force between a dyonic brane and an electric brane is computed and is found to vanish at a nontrivial critical separation. This equilibrium point is unstable. For smaller separations the branes coalesce to form a composite dyonic state, while for larger separations the branes run off to infinity. We suggest generalizations that will lead to potentials with stable local minima.

hep-th↗

arXiv2001

Einstein-Hilbert action on the brane for the bulk graviton

We find new closed string couplings on Dp-branes for the bosonic string. These couplings are quadratic in derivatives and therefore take the form of induced kinetic terms on the brane. For the graviton in particular we find the induced Einstein-Hilbert term as well as terms quadratic in the second fundamental tensor. We comment on tachyon dependences of these brane-localized couplings.

hep-th↗

arXiv2001

Solving the Hierarchy Problem with Brane Crystals

The brane world scenario advocated by Arkani-Hamed et al. transmutes the hierarchy problem into explaining why extra dimensions have sizes much larger than the fundamental scale. In this paper we discuss possible solutions to this problem by considering the compactified dimensions to be populated by a large number of branes in a crystal lattice. The experimental consequences of this scenario are described, including the presence of large energy gaps in the spectrum of Kaluza-Klein modes.

hep-ph↗

arXiv2000

A Note On Holographic Ward Identities

In this note we show how Ward identities may be derived for a quantum field theory dual of a string theory using the AdS/CFT correspondence. In particular associated with any gauge symmetry of the bulk supergravity theory there is a corresponding constraint equation. Writing this constraint in Hamilton-Jacobi form gives a generating functional for Ward identities in the dual QFT. We illustrate the method by considering various examples.

hep-th↗

arXiv1999

Mass spectrum of N=8 supergravity on AdS_2 \times S^2

An initial step is taken in investigating the duality between the near horizon region of a four dimensional extremal Reissner-Nordstrom black hole and the n-particle, N=4 Calogero model as conjectured by Gibbons and Townsend. Specifically we compute the mass spectrum of d=4, N=8 supergravity about the Bertotti-Robinson solution and find the corresponding set of conformal dimensions of states in the dual conformal quantum mechanics. We find that the dual states fill irreducible representations of the supergroup SU(1,1|2), and furthermore transform under various irreducible representations of the group SU(2) \times SU(6) spontaneously broken down from the E_{7(7)} duality group of N=8 supergravity.

hep-th↗

arXiv1998

The massless gravitino and the AdS/CFT correspondence

We solve the Dirichlet boundary value problem for the massless gravitino on $AdS_{d+1}$ space and compute the two-point function of the dual CFT supersymmetry currents using the $AdS$/CFT correspondence principle. We find analogously to the spinor case that the boundary data for the massless $(d+1)$ dimensional bulk gravitino field consists of only a $(d-1)$ dimensional gravitino.

hep-th↗

arXiv1998

Lattice Black Holes

We study the Hawking process on lattices falling into static black holes. The motivation is to understand how the outgoing modes and Hawking radiation can arise in a setting with a strict short distance cutoff in the free-fall frame. We employ two-dimensional free scalar field theory. For a falling lattice with a discrete time-translation symmetry we use analytical methods to establish that, for Killing frequency $ω$ and surface gravity $κ$ satisfying $κ\llω^{1/3}\ll 1$ in lattice units, the continuum Hawking spectrum is recovered. The low frequency outgoing modes arise from exotic ingoing modes with large proper wavevectors that "refract" off the horizon. In this model with time translation symmetry the proper lattice spacing goes to zero at spatial infinity. We also consider instead falling lattices whose proper lattice spacing is constant at infinity and therefore grows with time at any finite radius. This violation of time translation symmetry is visible only at wavelengths comparable to the lattice spacing, and it is responsible for transmuting ingoing high Killing frequency modes into low frequency outgoing modes.

hep-th↗

arXiv1997

Computing the spectrum of black hole radiation in the presence of high frequency dispersion: an analytical approach

We present a method for computing the spectrum of black hole radiation of a scalar field satisfying a wave equation with high frequency dispersion. The method involves a combination of Laplace transform and WKB techniques for finding approximate solutions to ordinary differential equations. The modified wave equation is obtained by adding a higher order derivative term suppressed by powers of a fundamental momentum scale $k_0$ to the ordinary wave equation. Depending on the sign of this new term, high frequency modes propagate either superluminally or subluminally. We show that the resulting spectrum of created particles is thermal at the Hawking temperature, and further that the out-state is a thermal state at the Hawking temperature, to leading order in $k_0$, for either modification.

hep-th↗

arXiv1994

Collapse of Kaluza-Klein Bubbles

Kaluza-Klein theory admits ``bubble" configurations, in which the circumference of the fifth dimension shrinks to zero on some compact surface. A three parameter family of such bubble initial data at a moment of time-symmetry (some including a magnetic field) has been found by Brill and Horowitz, generalizing the (zero-energy) ``Witten bubble" solution. Some of these data have negative total energy. We show here that all the negative energy bubble solutions start out expanding away from the moment of time symmetry, while the positive energy bubbles can start out either expanding or contracting. Thus it is unlikely that the negative energy bubbles would collapse and produce a naked singularity.

gr-qc↗