Armen Yeranyan

stu Black Holes Unveiled

The general solutions of the radial attractor flow equations for extremal black holes, both for non-BPS with non-vanishing central charge Z and for Z = 0, are obtained for the so-called stu model, the minimal rank-3 N = 2 symmetric supergravity in d = 4 space-time dimensions. Comparisons with previous results, as well as the fake supergravity (first order) formalism and an analysis of the BPS bound all along the non-BPS attractor flows and of the marginal stability of corresponding D-brane configurations, are given.

d=4 Black Hole Attractors in N=2 Supergravity with Fayet-Iliopoulos Terms

We generalize the description of the d = 4 Attractor Mechanism based on an eective black hole (BH) potential to the presence of a gauging which does not modify the derivatives of the scalars and does not involve hypermultiplets. The obtained results do not rely necessarily on supersymmetry, and they can be extended to d > 4, as well. Thence, we work out the example of the stu model of N = 2 supergravity in the presence of Fayet-Iliopoulos terms, for the supergravity analogues of the magnetic and D0 D6 BH charge congurations,

Universality of the superpotential for d=4 extremal black holes

Abstract We provide a general strategy to obtain the superpotential W for both BPS and non-BPS extremal black holes in N = 2 four-dimensional supergravities based on symmetric spaces. This extends the construction of W in terms of U-duality invariants that was presented in previous work on the t 3 model. As an application, we explicitly provide W and the solutions to the related gradient flows for the st 2 and stu models. The procedure is shown to hold also for the full N = 8 theory. The role of flat directions in moduli space is clarified.

First order flows for N=2 extremal black holes and duality invariants

Abstract We derive explicitly the superpotential W for the non-BPS branch of N = 2 extremal black holes in terms of duality invariants of special geometry. Although this is done for a one-modulus case (the t 3 model), the example gives Z ≠ 0 black holes and captures the basic distinction from previous attempts on the quadratic series (vanishing C tensor) and from the other Z = 0 cases. The superpotential W turns out to be a non-polynomial expression (containing radicals) of the basic duality invariant quantities. These are the same which enter in the quartic invariant I 4 for N = 2 theories based on symmetric spaces. Using the flow equations generated by W , we also provide the analytic general solution for the warp factor and for the scalar field supporting the non-BPS black holes.

Mirror Fermat Calabi-Yau Threefolds and Landau-Ginzburg Black Hole Attractors

We study black hole attractor equations for one-(complex structure)modulus Calabi-Yau spaces which are the mirror dual of Fermat Calabi-Yau threefolds (CY3s). When exploring non-degenerate solutions near the Landau-Ginzburg point of the moduli space of such 4-dimensional

Freudenthal Duality and Generalized Special Geometry

Department of Physics, Yerevan State UniversityAlex Manoogian St. 1, Yerevan, 0025, ArmeniaABSTRACTFreudenthal duality, introduced in [1] and defined as an anti-involution on the dyonic charge vector in d = 4space-time dimensions for those dualities admitting a quartic invariant, is proved to be a symmetry not only ofthe classical Bekenstein-Hawking entropy but also of the critical points of the black hole potential.Furthermore, Freudenthal duality is extended to any generalized special geometry, thus encompassing allN > 2 supergravities, as well as N = 2 generic special geometry, not necessarily having a coset space structure.

Two-Center Black Holes Duality-Invariants for stu Model and its lower-rank Descendants

We classify 2-center extremal black hole charge configurations through duality-invariant homogeneous polynomials, which are the generalization of the unique invariant quartic polynomial for single-center black holes based on homogeneous symmetric cubic special Ka hler geometries. A crucial role is played by a horizontal SL(p,R) symmetry group, which classifies invariants for p-center black holes. For p = 2, a (spin 2) quintet of quartic invariants emerge. We provide the minimal set of independent invariants for the rank-3 N=2, d = 4 stu model, and for its lower-rank descendants, namely, the rank-2 st2 and rank-1 t3 models; these models, respectively, exhibit seven, six, and five independent invariants. We also derive the polynomial relations among these and other duality invariants. In particular, the symplectic product of two charge vectors is not independent from the quartic quintet in the t3 model, but rather it satisfies a degree-16 relation, corresponding to a quartic equation for the square of the s...

Noncommutative quantum scattering in a central field

In this Letter the problem of noncommutative elastic scattering in a central field is considered. General formulas for the differential cross-section for two cases are obtained. For the case of high energy of an incident wave it is shown that the differential cross-section coincides with that on the commutative space. For the case in which noncommutativity yields only a small correction to the central potential it is shown that the noncommutativity leads to the redistribution of particles along the azimuthal angle, although the whole cross-section coincides with the commutative case.

On invariant structures of black hole charges

A bstractWe study “minimal degree” complete bases of duality- and “horizontal”- invariant homogeneous polynomials in the flux representation of two-centered black hole solutions in two classes of D = 4 Einstein supergravity models with symmetric vector multiplets’ scalar manifolds. Both classes exhibit an SL(2,

Quantum oscillator on CP{sup n} in a constant magnetic field

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