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Discrete Wilson Lines in F-Theory
Get PDFF-theory models are constructed where the 7-brane has a non-trivial fundamental group. The base manifolds used are a toric Fano variety and a smooth toric threefold coming from a reflexive polyhedron. The discriminant locus of the elliptically fibered Calabi-Yau fourfold can be chosen such that one irreducible component it is not simply connected (namely, an Enriques surface) and supports a non-Abelian gauge theory
Stabilizing All Kähler Moduli in Type IIB Orientifolds
Get PDFWe describe a simple and robust mechanism that stabilizes all Kähler moduli in Type IIB orientifold compactifications. This is shown to be possible with just one non-perturbative contribution to the superpotential coming from either a D3-instanton or D7-branes wrapped on an ample divisor. This moduli-stabilization mechanism is similar to and motivated by the one used in the fluxless G 2 compactifications of M -theory. After explaining the general idea, explicit examples of Calabi-Yau orientifolds with one and three Kähler moduli are worked out. We find that the stabilized volumes of all two-and four-cycles as well as the volume of the Calabi-Yau manifold are controlled by a single parameter, namely, the volume of the ample divisor. This feature would dramatically constrain any realistic models of particle physics embedded into such compactifications. Broad consequences for phenomenology are discussed, in particular the dynamical solution to the strong CP-problem within the frame-work
Two-Loop Crossover Scaling Functions of the O(N) Model
Get PDFUsing Environmentally Friendly Renormalization, we present an analytic calculation of the series for the renormalization constants that describe the equation of state for the O(N) model in the whole critical region. The solution of the beta-function equation, for the running coupling to order two loops, exhibits crossover between the strong coupling fixed point, associated with the Goldstone modes, and the Wilson-Fisher fixed point. The Wilson functions γ_λ, γ_φ and γ_φ^2, and thus the effective critical exponents associated with renormalization of the transverse vertex functions, also exhibit non-trivial crossover between these fixed points
AdS5 solutions in Einstein–Yang-Mills–Chern-Simons theory
Get PDFWe investigate static, spherically symmetric solutions of an Einstein-Yang-Mills-Chern-Simons system with negative cosmological constant, for an SO(6) gauge group. For a particular value of the Chern-Simons coefficient, this model can be viewed as a truncation of the five-dimensional maximal gauged supergravity and we expect that the basic properties of the solutions in the full model to persist in this truncation. Both globally regular, particle-like solutions and black holes are considered. In contrast with the Abelian case, the contribution of the Chern-Simons term is nontrivial already in the static, spherically symmetric limit. We find two types of solutions: the generic configurations whose magnetic gauge field does not vanish fast enough at infinity (although the spacetime is asymptotically AdS), whose mass function is divergent, and the special configurations, whose existence depends on the Chern–Simons term, which are endowed with finite mass. In the case of the generic configurations, we argue that the divergent mass implies a nonvanishing trace for the stress tensor of the dual d = 4 theory
The cosmological constant and the black hole equation of state
Get PDFThe thermodynamics of black holes in various dimensions are described in the presence of a negative cosmological constant which is treated as a thermodynamic variable, interpreted as a pressure in the equation of state. The black hole mass is then identified with the enthalpy rather than the internal energy, the Euclidean action is the Gibbs free energy rather than the Helmoholtz free energy and heat capacities are calculated at constant pressure not at constant volume. Quantum corrections to the enthalpy and the equation of state of the BTZ black hole are studied
Holomorphic and anti-holomorphic conductivity flows in the quantum Hall effect
Get PDFIt is shown that the flow diagrams for the conductivities in the quantum Hall effect, arising from two ostensibly very different proposals based on modular symmetry, are in fact identical. The β-functions are different, the rate at which the flow lines are traversed are different, but the tangents to the flow lines are the same in both cases, hence the flow diagrams are same in all aspects
Massive Hopfions
Get PDFThe Skyrme-Faddeev model is a (3 + 1)-dimensional model which has knotted, string-like, soliton solutions. In this paper we investigate a Skyrme-Faddeev model with an SO(3) symmetry breaking potential. We then rescale this model and take the mass to infinity. This infinite mass model is found to have compact knotted solutions. In all of the investigated massive models we find similar charged solutions as in the usual, m = 0, model. We also find that their energies follow a similar E ∼ Q 3/4 power growth as the m = 0 model