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Global embeddings for branes at toric singularities
Get PDFWe describe how local toric singularities, including the Toric Lego construction, can be embedded in compact Calabi-Yau manifolds. We study in detail the addition of D-branes, including non-compact flavor branes as typically used in semi-realistic model building. The global geometry provides constraints on allowable local models. As an illustration of our discussion we focus on D3 and D7-branes on (the partially resolved) (dP_0)^3 singularity, its embedding in a specific Calabi-Yau manifold as a hypersurface in a toric variety, the related type IIB orientifold compactification, as well as the corresponding F-theory uplift. Our techniques generalize naturally to complete intersections, and to a large class of F-theory backgrounds with singularities
Gauge-invariant correlation functions in light-cone superspace
Get PDFWe initiate a study of correlation functions of gauge-invariant operators in N = 4 super Yang-Mills theory using the light-cone superspace formalism. Our primary aim is to develop efficient methods to compute perturbative corrections to correlation functions. This analysis also allows us to examine potential subtleties which may arise when calculating off-shell quantities in light-cone gauge. We comment on the intriguing possibility that the manifest N = 4 supersymmetry in this approach may allow for a compact description of entire multiplets and their correlation functions
D3/D7 quark-gluon plasma with magnetically induced anisotropy
Get PDFWe study the effects of the temperature and of a magnetic field in the setup of an intersection of D3/D7 branes, where a large number of D7 branes is smeared in the transverse directions to allow for a perturbative solution in a backreaction parameter. The magnetic field sources an anisotropy in the plasma, and we investigate its physical consequences for the thermodynamics and energy loss of particles probing the system. In particular we comment on the stress-energy tensor of the plasma, the propagation of sound, the drag force of a quark moving through the medium and jet quenching
A General Vanishing Theorem
Get PDFLet E be a vector bundle and L be a line bundle over a smooth projective variety X. In this article, we give a condition for the vanishing of Dolbeault cohomology groups of the form H^p,q (X, S^α E ⊗ (∧^β)E ⊗ L) when S^(α+β)E ⊗ L is ample. This condition is shown to be invariant under the interchange of p and q. The optimality of this condition is discussed for some parameter values
Hypothese theorique concernant l’induction d’un champ gravitationnel de type vectoriel genere par le decplacement accelere des masses en mouvement
Get PDFNous proposons une théorie (G) du champ vectorielle G_μ(x) en s’appyant sur une construction analogue à la théorie électromagnétique (EM) et sur un principe d’induction de type gravitationnelle générée par des courants de masses accélérées. Il s’agit de présenter une première réflexion sur ce travail en construisant d’abord le Lagrangien L = −mc^2*G_μ(x)ẍ^μ (m est la masse et ẍ^μ l’accélération de la particule, G_μ le champ vectoriel), en discutant ensuite le principe d’induction puis en proposant les équations de champs. Nous regarderons ensuite les équations du mouvement à l’ordre des petites vitesses (ordre v/c) et établirons les équations qui décrivent un nouveau phénomène de type gravitomagnétique (GEM-G) prédit par la théorie (G) et analogues aux équations gravitomagnétiques (GEM) qui dérivent de la théorie de la relativité génerale (RG). En-fin, nous proposerons une première reflexion sur l’intégration de la théorie (G) au cadre général de la relativité et donc à la théorie Einsteinienne de la gravité (RG) et nous discutetons les implications conceptuelles d’une théorie (RG) complétée par l’ajout du champ G_μ
Where is the PdV term in the first law of black hole thermodynamics?
Get PDFTraditional treatments of the first law of black hole thermodynamics do not include a discussion of pressure and volume. We give an overview of recent developments proposing a definition of volume that can be used to extend the first law to include these appropriately. New results are also presenting relating to the critical point and the associated second order phase transition for a rotating black-hole in four-dimensional space-time which is asymptotically anti-de Sitter. In line with known results for a non-rotating charged black-hole, this phase transition is shown to be of Van der Waals type with mean field exponents
Counting points and Hilbert series in string theory
Get PDFThe problem of counting points is revisited from the perspective of reflexive 4-dimensional polytopes. As an application, the Hilbert series of the 473,800,776 reflexive polytopes (equivalently, their Calabi-Yau hypersurfaces) are computed
Discrete-time path distributions on Hilbert Space
Get PDFWe construct a path distribution representing the kinetic part of the Feynman path integral at discrete times similar to that defined by Thomas [1], but on a Hilbert space of paths rather than a nuclear sequence space. We also consider different boundary conditions and show that the discrete-time Feynman path integral is well-defined for suitably smooth potentials
Matrix geometries and matrix models
Get PDFWe study a two parameter single trace 3-matrix model with SO(3) global symmetry. The model has two phases, a fuzzy sphere phase and a matrix phase. Configurations in the matrix phase are consistent with fluctuations around a background of commuting matrices whose eigenvalues are confined to the interior of a ball of radius R = 2.0. We study the co-existence curve of the model and find evidence that it has two distinct portions one with a discontinuous internal energy yet critical fluctuations of the specific heat but only on the low temperature side of the transition and the other portion has a continuous internal energy with a discontinuous specific heat of finite jump. We study in detail the eigenvalue distributions of different observables