A bstractIt is known that time-dependent perturbations can enhance superconductivity and increase the critical temperature. If this phenomenon happens to high-Tc superconductors, one could obtain room-temperature superconductors, but this is still an open issue experimentally. Meanwhile, we would like to understand this phenomenon from gravity dual and see if the enhancement is possible for holographic superconductors. Previous work (arXiv:1104.4098[hep-th]) has studied this issue by adding a “time-dependent chemical potential”, but their analysis is questionable as a true dynamic equilibrium. In particular, the AdS boundary does not supply energy to the bulk spacetime in their setup. A more appropriate way to discuss the enhancement is to add a time-dependent vector potential, i.e., a time-dependent electric field. However, the enhancement does not occur for holographic superconductors.
Following the suggestion of hep-th/0506249 and hep-th/0612011, we represent quarter BPS dyons in = 4 supersymmetric string theories as string network configuration and explore the role of genus two surfaces in determining the spectrum of such dyons. Our analysis leads to the correct contour prescription for integrating the partition function to determine the spectrum in different domains of the moduli space separated by the walls of marginal stability.
The two-loop Euler-Heisenberg-type effective action for = 1 supersymmetric QED is computed within the background field approach. The background vector multiplet is chosen to obey the constraints DαWβ = D(αWβ) = const, but is otherwise completely arbitrary. Technically, this calculation proves to be much more laborious as compared with that carried out in hep-th/0308136 for = 2 supersymmetric QED, due to a lesser amount of supersymmetry. Similarly to Ritus' analysis of spinor and scalar QED, the two-loop renormalisation is carried out using proper-time cut-off regularisation. A closed-form expression is obtained for the holomorphic sector of the two-loop effective action, which is singled out by imposing a relaxed super self-duality condition.
In this work we propose new non-commutative gauge theories that describe the dynamics of branes localized along twisted conjugacy classes on group manifolds. Our proposal is based on a careful analysis of the exact microscopic solution and it generalizes the matrix models (“fuzzy gauge theories”) that are used to study e.g. the bound state formation of point-like branes in a curved background. We also construct a large number of classical solutions and interpret them in terms of condensation processes on branes localized along twisted conjugacy classes. AEI-2002-027 hep-th/0205123
We modify the first ISS model [K. Intriligator, N. Seiberg, D. Shih, JHEP 0604 (2006) 021, hep-th/0602239] by gauging a diagonal flavour symmetry. We add additional multiplets transforming as fundamentals and anti-fundamentals under the gauged flavour group. Their number is chosen such that the microscopic theory is asymptotically free whereas in the Seiberg dual (w.r.t. the colour group) it changes to an infrared free theory. Non-perturbative effects within the flavour group can correct the location of the supersymmetric vacuum. Statements about meta-stability of the susy breaking vacuum would require a two loop calculation. For general couplings, the question whether gauging flavour destabilises susy breaking remains open.
Abstract We present the explicit formulas for all spin matrix elements in 2D Ising model with the nearest neighbor interaction on the finite periodic square lattice. These expressions generalize the known results [Phys. Rev. D 19 (1979); hep-th/0107117; J. Stat. Phys. 110 (2003)] (coincide with them in the appropriate limits) and fulfill the test of straightforward transfer matrix calculations for finite N.
We investigate (super) string theory on AdS3 background based on an approach of free field realization. We demonstrate that this string theory can be reformulated as a string theory defined on a linear dilaton background along the transverse direction (“Liouville mode”) and compactified onto S1 along a light-like direction. Under this reformulation we analyze the physical spectrum as that of a free field system, and discuss the consequences when we turn on the Liouville potential. The discrete light-cone momentum in our framework is naturally interpreted as the “winding number” of the long string configuration and is identified with the spectral flow parameter that is introduced in the recent work by Maldacena and Ooguri (hep-th/0001053). Moreover we show that there exist infinite number of the on-shell chiral primary states possessing the different light-cone momenta and the spectral flow consistently acts on the space of chiral primaries. We observe that they are also chiral primaries in the sense of space–time (or the conformal theory of long string) and the spectrum of space–time U(1)R charge is consistent with the expectation from the AdS3/CFT2-duality. We also clarify the correspondence between our framework and the symmetric orbifold theory of multiple long string system (K. Hosomichi, Y. Sugawara, JHEP 9907 (1999) 027, hep-th/9905004).
Recently a five-dimensional Kaluza-Klein black hole solution with squashed horizon has been found in [H. Ishihara, K. Matsuno, hep-th/0510094]. The black hole space-time is asymptotically locally flat and has a spatial infinity S-1 hooked right arrow S-2. By using "boundary counterterm" method and generalized Abbott-Deser method, we calculate the mass of this black hole. When an appropriate background is chosen, the generalized Abbott-Deser method gives the same mass as the "boundary counterterm" method. The mass is found to satisfy the first law of black hole thermodynamics. The thermodynamic properties of the Kaluza-Klein black hole are discussed and are compared to those of its undeformed counterpart, a five-dimensional Reissner-Nordstrom black hole. (c) 2006 Elsevier B.V. All rights reserved.
FollowingGubser,KlebanovandPolyakov(hep-th/0204051),westudystrings in AdS black hole backgrounds. With respect to the pure AdS case, rotating strings are replaced by orbiting strings. We interpret these orbiting strings as CFT states of large spin similar to glueballs propagating through a gluon plasma. The energy and the spin of the orbiting string conflgurations are associated with the energy and the spin of states in the dual flnite temperatureN =4 SYM theory. We analyse in particular the limiting cases of short and long strings. Moreover, we perform a thermodynamic study of the angular momentum transfer from the glueball to the plasma by considering string orbits aroundrotatingAdSblackholes. Weflndthatstandardexpectations,suchasthecomplete thermal dissociation of the glueball, are borneout after subtle propertiesof rotating AdS black holes aretaken into account.