Recursos de colección
Bonelli, Giulio; Tanzini, Alessandro
We study cohomological gauge theories on total spaces of holomorphic line bundles over complex manifolds and obtain their reduction to the base manifold by $U(1)$-equivariant localization of the path integral. We exemplify this general mechanism by proving via exact path integral localization a reduction for local curves conjectured in hep-th/0411280, relevant to the calculation of black hole entropy/Gromov–Witten invariants. Agreement with the four-dimensional gauge theory is recovered by taking into account in the latter non-trivial contributions coming from one-loop fluctuation determinants at the boundary of the total space. We also study a class of abelian gauge theories on Calabi–Yau local...
Fujii, Shigeyuki; Kanno, Hiroaki; Moriyama, Sanefumi; Okada, Soichi
Sadel, Christian; Schulz-Baldes, Hermann
For a one-dimensional discrete Schrödinger operator with a weakly coupled potential given by a strongly mixing dynamical system with power law decay of correlations, we derive for all energies including the band edges and the band center a perturbative formula for the Lyapunov exponent. Under adequate hypothesis, this shows that the Lyapunov exponent is positive on the whole spectrum. This in turn implies that the Hausdorff dimension of the spectral measure is zero and that the associated quantum dynamics grows at most logarithmically in time.
Fjelstad, Jens; Fuchs, Jurgen; Runkel, Ingo; Schweigert, Christoph
We study the sewing constraints for rational two-dimensional conformal field theory on oriented surfaces with possibly nonempty boundary. The boundary condition is taken to be the same on all segments of the boundary. The following uniqueness result is established: for a solution to the sewing constraints with nondegenerate closed state vacuum and nondegenerate two-point correlators of boundary fields on the disk and of bulk fields on the sphere, up to equivalence all correlators are uniquely determined by the one-, two- and three-point correlators on the disk.
¶ Thus for any such theory every consistent collection of correlators can be obtained by...
Ikeda, Noriaki; Tokunaga, Tatsuya
We construct topological string and topological membrane actions with a nontrivial 3-form flux $H$ in arbitrary dimensions. These models realize Bianchi identities with a nontrivial $H$ flux as consistency conditions. Especially, we discuss the models with a generalized $SU(3)$ structure, a generalized G_{2} structure and a generalized Spin(7) structure. These models are constructed from the AKSZ formulation of the Batalin–Vilkovisky formalism.
Barbot, Thierry
This paper is the continuation of Causal properties of AdS-isometry groups I: causal actions and limit sets. We essentially prove that the family of strongly causal spacetimes defined in Causal properties of AdS-isometry groups I: causal actions and limit sets associated to generic achronal subsets in Ein_{2} contains all the examples of BTZ multi-blackholes. It provides new elements for the global description of these multiblack-holes. We also prove that any strongly causal spacetime locally modeled on the anti-de Sitter space admits a well-defined maximal strongly causal conformal boundary locally modeled on Ein_{2}.
Gerhardt, Claus
We prove that the leaves of an inverse mean curvature flow provide a foliation of a future end of a cosmological spacetime $N$ under the necessary and sufficient assumptions that $N$ satisfies a future mean curvature barrier condition and a strong volume decay condition. Moreover, the flow parameter t can be used to define a new physically important time function.
Mena, Filipe C.; Natário, José; Tod, Paul
We match collapsing inhomogeneous as well as spatially homogeneous but
anisotropic spacetimes to vacuum static exteriors with a negative cosmological
constant and planar or hyperbolic symmetry. The collapsing interiors include the
inhomogeneous solutions of Szekeres and of Barnes, which in turn include the
Lemaître–Tolman and the McVittie solutions. The collapse can result in toroidal
or higher genus asymptotically $AdS$ black holes.
Becker, Melanie; Tseng, Li-Sheng; Yau, Shing-Tung
Santillan, Osvaldo
Several Einstein–Sasaki seven-metrics appearing in the physical literature are ﬁbred over four-dimensional Kähler–Einstein metrics. Instead we consider here the natural Kähler–Einstein metrics deﬁned over the twistor space $Z$ of any quaternion Kähler four-space, together with the corresponding Einstein–Sasaki metrics. We work out an explicit expression for these metrics and we prove that they are indeed tri-Sasaki. Moreover, we present a squashed version of them which is of weak $G2$ holonomy. We focus in examples with three commuting Killing vectors and we extend them to supergravity backgrounds with T^{3} isometry, some of them with $AdS_{4} × X_{7}$ near horizon limit and...
Caporaso, Nicola; Cirafici, Michele; Griguolo, Luca; Pasquetti, Sara; Seminara, Domenico; Szabo, Richard J.
We study the relations between two-dimensional Yang–Mills theory on the torus, topological string theory on a Calabi–Yau threefold whose local geometry is the sum of two line bundles over the torus, and Chern–Simons theory on torus bundles. The chiral partition function of the Yang–Mills gauge theory in the large $N$ limit is shown to coincide with the topological string amplitude computed by topological vertex techniques. We use Yang–Mills theory as an efficient tool for the computation of Gromov–Witten invariants and derive explicitly their relation with Hurwitz numbers of the torus. We calculate the Gopakumar–Vafa invariants, whose integrality gives a non-trivial...
Beisert, Niklas
Bernardoni, Fabio; Cacciatori, Sergio L.; Cerchiai, Bianca L.; Scotti, Antonio
Andersson, Lars; Mars, Marc; Simon, Walter
Adams, Allan; Ernebjerg, Morten; Lapan, Joshua M.
Bergman, Aaron
I discuss the relation of Hochschild cohomology to the physical states in
the closed topological string. This allows a notion of deformation intrinsic
to the derived category. I use this to identify deformations of a quiver
gauge theory associated to a D-branes at a singularity with generalized
deformations of the geometry of the resolution of the singularity. An
explicit map is given from noncommutative deformations (i.e., B-fields)
to terms in the superpotential.
Andreas, Björn; Curio, Gottfried
Wijnholt, Martijn P.
Pande, Ashwin S.
We study topological T-duality for spaces with a semi-free $S^{1}$-action with
isolated fixed points. Physically, these correspond to spacetimes containing
Kaluza–Klein monopoles. We demonstrate that the physical dyonic coordinate of
such spaces has an analogue in our formalism. By analogy with the Dirac
monopole, we study these spaces as gerbes. We study the effect of topological
T-duality on these gerbes.
Lüst, Dieter; Reffert, Susanne; Scheidegger, Emanuel; Stieberger, Stephan
We discuss the resolution of toroidal orbifolds. For the resulting smooth
Calabi–Yau manifolds, we calculate the intersection ring and determine the
divisor topologies. In a next step, the orientifold quotients are
constructed..