A new two-faced scalar solution and cosmological SUSY breaking

We propose a possible new way to resolve the long standing problem of strong supersymmetry breaking coexisting with a small cosmological constant. We consider a scalar component of a minimally coupled N=1 supermultiplet in a general Friedmann-Robertson-Walker (FRW) expanding universe. We argue that a tiny term, proportional to H^2 ~ 10^(-122) in Plank's units, appearing in the field equations due to this expansion will provide both, the small vacuum energy and the heavy mass of the scalar supersymmetric partner. We present a non-perturbative solution for the scalar field with an unusual dual-frequency behavior. This solution has two characteristic mass scales related to the Hubble parameter as H^(1/4) and H^(1/2) measured in Plank's units.Comment: 5 pages, 5 figure

Supersymmetric Multiple Basin Attractors

We explain that supersymmetric attractors in general have several critical points due to the algebraic nature of the stabilization equations. We show that the critical values of the cosmological constant of the adS_5 vacua are given by the topological (moduli independent) formulae analogous to the entropy of the d=5 supersymmetric black holes. We present conditions under which more than one critical point is available (for black hole entropy as well as to the cosmological constant) so that the system tends to its own locally stable attractor point. We have found several families of Z_2-symmetric critical points where the central charge has equal absolute values but opposite signs in two attractor points. We present examples of interpolating solutions and discuss their generic features.Comment: 14 pages, 1 fig, JHEP, added proof of positivity of vector metric at critical points, analysis of interpolating solutions, and ref

Excision of singularities by stringy domain walls

We study supersymmetric domain walls on S1/Z2 orbifolds. The supergravity solutions in the bulk are given by the attractor equation associated with Calabi–Yau (CY) spaces and have a naked space–time singularity at some |ys|. We are looking for possibilities to cut off this singularity with the second wall by a stringy mechanism. We use the collapse of the CY cycle at |yc| which happens before and at a finite distance from the space–time singularity. In our example with three Kähler moduli the second wall is at the end of the moduli space at |yc| where also the enhancement of SU(2) gauge symmetry takes place so that |ye| = |yc|1/R duality. The position of the enhançon is given by the equation R(|ye|) = 1

On black holes and d-branes

N=2 supersymmetric extreme black holes associated with the different types of the moduli space are investigated. The explicit solutions for the black hole entropy as a function of the electric and magnetic charges of the black hole are found. Starting with the simple case of two moduli and two electric and magnetic charges ( qΛ and p^ with Λ = 0,1) the investigation proceeds to the more complicated moduli spaces, such as the most general form of the Calabi-Yau moduli space with the arbitrary number of moduli fields. The global N=4 Supersymmetry transformations for the gauge-fixed K symmetric Born-Infeld D3 brane action are calculated in the fiat background using Killing gauge. One loop corrections to the effective Lagrangian for the D3 brane are found

Sediment Transport in River Flows: New Approaches and Formulas

A new method for estimating the total sediment discharge, as built on balance of power acting to moving sediment particle in “water stream-bottom sediments—sediments” system, enables consideration of interrelated influence of hydraulic variables state of flow and sediment. At the same time, the basic sticking point of river hydraulics, that is, interaction of fluid and bottom, is specified not from the part of fluid boundary, but from that of bottom sediments and their properties, well studied in soil science. Setting the size of bottom sediments by means of their qualitative characteristics allows avoiding calculation errors that occur when using specific values of quantiles of bottom sediments in calculations. Consideration of the critical velocities and the phase hydraulic space of the flow allowed obtaining the equations for transporting capacity of the flow, suspended, and bed load discharges

Generalized Attractor Points in Gauged Supergravity

The attractor mechanism governs the near-horizon geometry of extremal black holes in ungauged 4D N=2 supergravity theories and in Calabi-Yau compactifications of string theory. In this paper, we study a natural generalization of this mechanism to solutions of arbitrary 4D N=2 gauged supergravities. We define generalized attractor points as solutions of an ansatz which reduces the Einstein, gauge field, and scalar equations of motion to algebraic equations. The simplest generalized attractor geometries are characterized by non-vanishing constant anholonomy coefficients in an orthonormal frame. Basic examples include Lifshitz and Schrodinger solutions, as well as AdS and dS vacua. There is a generalized attractor potential whose critical points are the attractor points, and its extremization explains the algebraic nature of the equations governing both supersymmetric and non-supersymmetric attractors.Comment: 31 pages, LaTeX; v2, references fixed; v3, minor changes, version to appear in Phys. Rev.

Domain Walls with Strings Attached

We have constructed a bulk & brane action of IIA theory which describes a pair of BPS domain walls on S_1/Z_2, with strings attached. The walls are given by two orientifold O8-planes with coincident D8-branes and `F1-D0'-strings are stretched between the walls. This static configuration satisfies all matching conditions for the string and domain wall sources and has 1/4 of unbroken supersymmetry.Comment: 12 pages, JHE