Anomalies and Hawking fluxes from the black holes of topologically massive gravity

The anomaly cancelation method proposed by Wilczek et al. is applied to the black holes of topologically massive gravity (TMG) and topologically massive gravito-electrodynamics (TMGE). Thus the Hawking temperature and fluxes of the ACL and ACGL black holes are found. The Hawking temperatures obtained agree with the surface gravity formula. Both black holes are rotating and this gives rise to appropriate terms in the effective U(1)$\mathrm{U}(1)$ gauge field of the reduced (1+1)$(1+1)$-dimensional theory. It is found that the terms in this U(1)$\mathrm{U}(1)$ gauge field correspond exactly to the correct angular velocities on the horizon of both black holes as well as the correct electrostatic potential of the ACGL black hole. So the results for the Hawking fluxes derived here from the anomaly cancelation method, are in complete agreement with the ones obtained from integrating the Planck distribution.     

Black holes on gravitational instantons

In this paper, we classify and construct five-dimensional black holes on gravitational instantons in vacuum Einstein gravity, with R×U(1)×U(1)$\mathbb{R}\times U(1)\times U(1)$ isometry. These black holes have spatial backgrounds which are Ricci-flat gravitational instantons with U(1)×U(1)$U(1)\times U(1)$ isometry, and are completely regular space–times outside the event horizon. Most of the known exact five-dimensional vacuum black-hole solutions can be classified within this scheme. Amongst the new space–times presented are static black holes on the Euclidean Kerr and Taub-bolt instantons. We also present a rotating black hole on the Eguchi–Hanson instanton.     

O-BTZ: Orientifolded BTZ black hole

Banados–Teitelboim–Zanelli (BTZ) black holes are constructed by orbifolding AdS₃ geometry by boost transformations of its O(2,2)$O(2,2)$ isometry group. Here we construct a new class of solutions to AdS₃ Einstein gravity, orientifolded BTZ or O-BTZ   for short, which in general, besides the usual BTZ orbifolding, involve orbifolding (orientifolding) by a Z₂${\mathbb{Z}}_2$ part of O(2,2)$O(2,2)$ isometry group. This Z₂${\mathbb{Z}}_2$ is chosen such that it changes the orientation on AdS₃ while keeping the orientation on its 2D conformal boundary. O-BTZ solutions exhaust all un-oriented AdS₃ black hole solutions, as BTZ black holes constitute all oriented AdS₃ black holes. O-BTZ, similarly to BTZ black holes, are stationary, axisymmetric asymptotically AdS₃ geometries with two asymptotic charges, mass and angular momentum.     

Discrete gauge symmetries in discrete MSSM-like orientifolds

Motivated by the necessity of discrete _ZN${\mathbb{Z}}_N$ symmetries in the MSSM to insure baryon stability, we study the origin of discrete gauge symmetries from open string sector U(1)$U(1)$?s in orientifolds based on rational conformal field theory. By means of an explicit construction, we find an integral basis for the couplings of axions and U(1)$U(1)$ factors for all simple current MIPFs and orientifolds of all 168 Gepner models, a total of 32 990 distinct cases. We discuss how the presence of discrete symmetries surviving as a subgroup of broken U(1)$U(1)$?s can be derived using this basis. We apply this procedure to models with MSSM chiral spectrum, concretely to all known U(3)×U(2)×U(1)×U(1)$U(3)\times U(2)\times U(1)\times U(1)$ and U(3)×Sp(2)×U(1)×U(1)$U(3)\times \mathit{Sp}(2)\times U(1)\times U(1)$ configurations with chiral bi-fundamentals, but no chiral tensors, as well as some SU(5)$\mathit{SU}(5)$ GUT models. We find examples of models with _Z2${\mathbb{Z}}_2$ (R-parity) and _Z3${\mathbb{Z}}_3$ symmetries that forbid certain B and/or L violating MSSM couplings. Their presence is however relatively rare, at the level of a few percent of all cases.     

Six-dimensional Yang black holes in dilaton gravity

We study the six-dimensional dilaton gravity Yang black holes of Bergshoeff, Gibbons and Townsend, which carry (1,−1)$(1,-1)$ charge in SU(2)×SU(2)$\mathit{SU}(2)\times \mathit{SU}(2)$ gauge group. We find what values of the asymptotic parameters (mass and scalar charge) lead to a regular horizon, and show that there are no regular solutions with an extremal horizon.     

Rotating Einstein–Maxwell–dilaton black holes in D dimensions

We construct exact charged rotating black holes in Einstein–Maxwell–dilaton theory in D   spacetime dimensions, D?5$D?5$, by embedding the D  -dimensional Myers–Perry solutions in D+1$D+1$ dimensions, and performing a boost with a subsequent Kaluza–Klein reduction. Like the Myers–Perry solutions, these black holes generically possess N=[(D−1)/2]$N=[(D-1)/2]$ independent angular momenta. We present the global and horizon properties of these black holes, and discuss their domains of existence.     

Differential operator realizations of superalgebras and free field representations of corresponding current algebras

Based on the particular orderings introduced for the positive roots of finite-dimensional basic Lie superalgebras, we construct the explicit differential operator representations of the osp(2r|2n)$\mathit{osp}(2r|2n)$ and osp(2r+1|2n)$\mathit{osp}(2r+1|2n)$ superalgebras and the explicit free field realizations of the corresponding current superalgebras ospk_(2r|2n)$\mathit{osp}{(2r|2n)}_k$ and ospk_(2r+1|2n)$\mathit{osp}{(2r+1|2n)}_k$ at an arbitrary level k. The free field representations of the corresponding energy–momentum tensors and screening currents of the first kind are also presented.     

Model building by coset space dimensional reduction in eight-dimensions

We investigate gauge-Higgs unification models in eight-dimensional spacetime where extra-dimensional space has the structure of a four-dimensional compact coset space. The combinations of the coset space and the gauge group in the eight-dimensional spacetime of such models are listed. After the dimensional reduction of the coset space, we identified SO(10)$\mathrm{SO}(10)$, SO(10)×U(1)$\mathrm{SO}(10)\times \mathrm{U}(1)$ and SO(10)×U(1)×U(1)$\mathrm{SO}(10)\times \mathrm{U}(1)\times \mathrm{U}(1)$ as the possible gauge groups in the four-dimensional theory that can accomodate the Standard Model and thus is phenomenologically promising. Representations for fermions and scalars for these gauge groups are tabulated.     

Phantom and non-phantom dark energy: The cosmological relevance of non-locally corrected gravity

In this Letter we have investigated the cosmological dynamics of non-locally corrected gravity involving a function of the inverse d'Alembertian of the Ricci scalar, f(^□−1R)$f({\square }^{\mathrm{-1}}R)$. Casting the dynamical equations into local form, we derive the fixed points of the dynamics and demonstrate the existence and stability of a one parameter family of dark energy solutions for a simple choice, f(^□−1R)∼exp(α^□−1R)$f({\square }^{\mathrm{-1}}R)\sim \exp (\alpha {\square }^{\mathrm{-1}}R)$. The effective EoS parameter is given by, weff=(α−1)/(3α−1)$w_{\mathrm{eff}}=(\alpha -1)/(3\alpha -1)$ and the stability of the solutions is guaranteed provided that 1/3<α<2/3$1/3<\alpha <2/3$. For 1/3<α<1/2$1/3<\alpha <1/2$ and 1/2<α<2/3$1/2<\alpha <2/3$, the underlying system exhibits phantom and non-phantom behavior respectively; the de Sitter solution corresponds to α=1/2$\alpha =1/2$. For a wide range of initial conditions, the system mimics dust like behavior before reaching the stable fixed point. The late time phantom phase is achieved without involving negative kinetic energy fields. A brief discussion on the entropy of de Sitter space in non-local model is included.     

Mass mixing,the fourth generation,and the kinematic Higgs mechanism

We describe how to construct explicit chiral fermion mass terms using Dirac–Kähler (DK) spinors. Classical massive DK spinors are shown to be equivalent to four generations of Dirac spinors with equal mass coupled to a background U(2,2)$U(2,2)$ gauge field. Quantization breaks U(2,2)$U(2,2)$ to U(2)×U(2)$U(2)\times U(2)$, lifts mass spectrum degeneracy, and generates a non-trivial CKM mixing.     

Supersymmetric quantum mechanics of magnetic monopoles: A case study

We study, in detail, the supersymmetric quantum mechanics of charge-(1,1)$(1,1)$ monopoles in N=2$N=2$ supersymmetric Yang–Mills–Higgs theory with gauge group SU(3)$\mathit{SU}(3)$ spontaneously broken to U(1)×U(1)$U(1)\times U(1)$. We use the moduli space approximation of the quantised dynamics, which can be expressed in two equivalent formalisms: either one describes quantum states by Dirac spinors on the moduli space, in which case the Hamiltonian is the square of the Dirac operator, or one works with anti-holomorphic forms on the moduli space, in which case the Hamiltonian is the Laplacian acting on forms. We review the derivation of both formalisms, explicitly exhibit their equivalence and derive general expressions for the supercharges as differential operators in both formalisms. We propose a general expression for the total angular momentum operator as a differential operator, and check its commutation relations with the supercharges. Using the known metric structure of the moduli space of charge-(1,1)$(1,1)$ monopoles we show that there are no quantum bound states of such monopoles in the moduli space approximation. We exhibit scattering states and compute corresponding differential cross sections.     

Comment on: “Construction of bound entangled edge states with special ranks” [Phys. Lett. A 359 (2006) 603]

In a Letter by Clarisse [L. Clarisse, Phys. Lett. A 359 (2006) 603–607] the open problem of the existence of (5,5)$(5,5)$ and (6,6)$(6,6)$ PPT edge states has been solved. Here we report the existence of another large class of (5,5)$(5,5)$ entangled edge states with positive partial transposes. We also give a PPT edge state with range dimensions (6,6)$(6,6)$.     

The nature of ZZ branes

In minimal non-critical string theory we show that the principal (r,s)$(r,s)$ ZZ brane can be viewed as the basic (1,1)$(1,1)$ ZZ boundary state tensored with the (r,s)$(r,s)$ Cardy boundary state. In this sense there exists only one ZZ boundary state, the basic (1,1)$(1,1)$ boundary state.     

Towards the MSSM from F-theory

We study the MSSM in F-theory. Its group is the commutant to a structure group SU(5)×UY₍₁₎$\mathit{SU}(5)\times U{(1)}_Y$ of a gauge bundle in E₈$E_8$. The spectrum contains three generations of quarks and leptons plus vectorlike electroweak and colored Higgses. The minimal MSSM Yukawa couplings with matter parity is obtained at the renormalizable level.