Results for "Dietmar Klemm"

total 587took 0.14s
Nut-charged black holes in matter-coupled N=2, D=4 gauged supergravityMar 28 2012Using the results of arXiv:0804.0009, where all timelike supersymmetric backgrounds of N=2, D=4 matter-coupled supergravity with Fayet-Iliopoulos gauging were classified, we construct genuine nut-charged BPS black holes in AdS_4 with nonconstant moduli. ... More
Black string first order flow in N=2, d=5 abelian gauged supergravityOct 24 2016Nov 08 2016We derive both BPS and non-BPS first-order flow equations for magnetically charged black strings in five-dimensional N=2 abelian gauged supergravity, using the Hamilton-Jacobi formalism. This is first done for the coupling to vector multiplets only and ... More
Rotating BPS black holes in matter-coupled AdS(4) supergravityMar 24 2011Using the general recipe given in arXiv:0804.0009, where all timelike supersymmetric solutions of N=2, D=4 gauged supergravity coupled to abelian vector multiplets were classified, we construct genuine rotating supersymmetric black holes in AdS(4) with ... More
Some Aspects of the de Sitter/CFT CorrespondenceJun 26 2001Jan 22 2002We discuss several aspects of the proposed correspondence between quantum gravity on de Sitter spaces and Euclidean conformal field theories. The central charge appearing in the asymptotic symmetry algebra of three-dimensional de Sitter space is derived ... More
Topological Black Holes in Weyl Conformal GravityAug 19 1998We present a class of exact solutions of Weyl conformal gravity, which have an interpretation as topological black holes. Solutions with negative, zero or positive scalar curvature at infinity are found, the former generalizing the well-known topological ... More
Four-dimensional black holes with unusual horizonsJan 14 2014Mar 21 2014We show that in presence of a cosmological constant or, more generally, of a scalar potential, there can exist actually more possibilities for the horizon geometry of a four-dimensional black hole than the hitherto known spherical, hyperbolic or flat ... More
Dualities in D=5, N=2 Supergravity, Black Hole Entropy, and AdS Central ChargesDec 21 2000The issue of microstate counting for general black holes in D=5, N=2 supergravity coupled to vector multiplets is discussed from various viewpoints. The statistical entropy is computed for the near-extremal case by using the central charge appearing in ... More
Black holes and singularities in string theoryOct 05 2004Nov 10 2004This is a summary of a lecture I gave at the workshop on dynamics and thermodynamics of black holes and naked singularities at Politecnico Milano. It is directed to a non-expert audience and reviews several ways in which string theory accounts for black ... More
Rotating Black Branes wrapped on Einstein SpacesNov 13 1998Nov 19 1998We present new rotating black brane solutions which solve Einstein's equations with cosmological constant $\Lambda$ in arbitrary dimension $d$. For negative $\Lambda$, the branes naturally appear in AdS supergravity compactifications, and should therefore ... More
BPS Black Holes in Gauged N=4, D=4 SupergravityOct 13 1998Jan 19 1999We find solutions of the bosonic sector of gauged N=4, D=4 SU(2) $\times$ SU(2) supergravity, which represent dilaton black holes with toroidal or spherical event horizons. The axion is consistently truncated, and the gauge group is broken to U(1) $\times$ ... More
Nonextremal black holes in gauged supergravity and the real formulation of special geometryJul 11 2012Oct 04 2012We give a rather general recipe for constructing nonextremal black hole solutions to N=2, D=4 gauged supergravity coupled to abelian vector multiplets. This problem simplifies considerably if one uses the formalism developed in arXiv:1112.2876, based ... More
All null supersymmetric backgrounds of N=2, D=4 gauged supergravity coupled to abelian vector multipletsFeb 24 2009May 23 2009The lightlike supersymmetric solutions of N=2, D=4 gauged supergravity coupled to an arbitrary number of abelian vector multiplets are classified using spinorial geometry techniques. The solutions fall into two classes, depending on whether the Killing ... More
De Sitter Gravity and Liouville TheoryMar 28 2002May 02 2002We show that the spectrum of conical defects in three-dimensional de Sitter space is in one-to-one correspondence with the spectrum of vertex operators in Liouville conformal field theory. The classical conformal dimensions of vertex operators are equal ... More
Geometry of Killing spinors in neutral signatureApr 10 2015Sep 09 2015We classify the supersymmetric solutions of minimal $N=2$ gauged supergravity in four dimensions with neutral signature. They are distinguished according to the sign of the cosmological constant and whether the vector field constructed as a bilinear of ... More
Black holes in Goedel-type universes with a cosmological constantJan 30 2004Jun 23 2004We discuss supersymmetric black holes embedded in a Goedel-type universe with cosmological constant in five dimensions. The spacetime is a fibration over a four-dimensional Kaehler base manifold, and generically has closed timelike curves. Asymptotically ... More
Magnetic charges in the AdS(4) superalgebra osp(4|2)May 24 2010Dec 01 2010We discuss the issue of how to include magnetic charges in the AdS(4) superalgebra osp(4|2). It is shown that the usual way of introducing a pseudoscalar central charge on the right hand side of the basic anticommutator does not work, because this breaks ... More
Black holes in an expanding universe and supersymmetryNov 05 2015Dec 12 2015This paper analyzes the supersymmetric solutions to five and six-dimensional minimal (un)gauged supergravities for which the bilinear Killing vector constructed from the Killing spinor is null. We focus on the spacetimes which admit an additional ${\rm ... More
Black holes in an expanding universe from fake supergravityDec 21 2012In arXiv:0902.4814, a general recipe to construct fake supersymmetric solutions to fake N=2, d=4 gauged supergravity coupled to abelian vector multiplets was presented. We use these results to find new multi-centered black hole solutions in an asymptotically ... More
The CFT dual of AdS gravity with torsionMay 23 2007Jul 30 2007We consider the Mielke-Baekler model of three-dimensional AdS gravity with torsion, which has gravitational and translational Chern-Simons terms in addition to the usual Einstein-Hilbert action with cosmological constant. It is shown that the topological ... More
Einstein manifolds with torsion and nonmetricityNov 28 2018Manifolds endowed with torsion and nonmetricity are interesting both from the physical and the mathematical points of view. In this paper, we generalize some results presented in the literature. We study Einstein manifolds in d dimensions with nonvanishing ... More
The Asymptotic Dynamics of de Sitter Gravity in three DimensionsOct 03 2001Nov 17 2001We show that the asymptotic dynamics of three-dimensional gravity with positive cosmological constant is described by Euclidean Liouville theory. This provides an explicit example of a correspondence between de Sitter gravity and conformal field theories. ... More
Rotating black holes in an expanding universe from fake supergravityMay 21 2014Using the recipe of arXiv:0902.4814, where all fake supersymmetric backgrounds of matter-coupled fake N=2, d=4 gauged supergravity were classified, we construct dynamical rotating black holes in an expanding FLRW universe. This is done for two different ... More
Supersymmetry of the C-metric and the general Plebanski-Demianski solutionMar 13 2013Jun 18 2013We derive the necessary and sufficient conditions under which the general Plebanski-Demianski (PD) solution of Einstein-Maxwell theory with a negative cosmological constant admits Killing spinors. We consider in detail two different scaling limits of ... More
Quantum Properties of Topological Black HolesMar 17 1998Jun 12 1998We examine quantum properties of topological black holes which are asymptotically anti--de Sitter. First, massless scalar fields and Weyl spinors which propagate in the background of an anti--de Sitter black hole are considered in an exactly soluble two--dimensional ... More
First order flow equations for nonextremal black holes in AdS (super)gravityJun 19 2017Sep 28 2017We consider electrically charged static nonextremal black holes in $d$-dimensional Einstein-Maxwell-(A)dS gravity, whose horizon is a generic Einstein space in $d-2$ dimensions. It is shown that for this system the Hamilton-Jacobi equation is exactly ... More
Nonextremal black holes in gauged supergravity and the real formulation of special geometry IINov 07 2012In arXiv:1207.2679 a new prescription for finding nonextremal black hole solutions to N=2, D=4 Fayet-Iliopoulos gauged supergravity was presented, and explicit solutions of various models containing one vector multiplet were constructed. Here we use the ... More
The timelike half-supersymmetric backgrounds of N=2, D=4 supergravity with Fayet-Iliopoulos gaugingMar 15 2010Subject to some relatively mild assumptions, we derive the complete form of all timelike half-supersymmetric solutions to N=2, D=4 gauged supergravity coupled to an arbitrary number of abelian vector multiplets. This is done using spinorial geometry techniques. ... More
On the Thermodynamics of Goedel Black HolesNov 25 2004After a brief review of Goedel-type universes in string theory, we discuss some intriguing properties of black holes immersed in such backgrounds. Among these are the upper bound on the entropy that points towards a finite-dimensional Hilbert space of ... More
Multi-centered black holes with a negative cosmological constantNov 27 2013We present a recipe that allows to construct multi-centered black holes embedded in an arbitrary FLRW universe. These solutions are completely determined by a function satisfying the conformal Laplace equation on the spatial slices $\text{E}^3$, $\text{S}^3$ ... More
Aspects of Quantum Gravity in de Sitter SpacesJul 29 2004Nov 11 2004In these lectures we give a review of recent attempts to understand quantum gravity on de Sitter spaces. In particular, we discuss the holographic correspondence between de Sitter gravity and conformal field theories proposed by Hull and by Strominger, ... More
Fluid dynamics on ultrastatic spacetimes and dual black holesApr 01 2014Jul 09 2014We show that the classification of shearless and incompressible stationary fluid flows on ultrastatic manifolds is equivalent to classifying the isometries of the spatial sections. For a flow on R x S$^2$ this leaves only one possibility, since on the ... More
Supersymmetric AdS_4 black holes and attractorsNov 25 2009Using the general recipe given in arXiv:0804.0009, where all timelike supersymmetric solutions of N=2, D=4 gauged supergravity coupled to abelian vector multiplets were classified, we construct the first examples of genuine supersymmetric black holes ... More
All Supersymmetric Solutions of N=2, D=4 Gauged SupergravityJul 02 2003Oct 08 2003We classify all supersymmetric solutions of minimal gauged supergravity in four dimensions. There are two classes of solutions that are distinguished by the norm of the Killing vector constructed from the Killing spinor. If the Killing vector is timelike, ... More
Supersymmetry of Anti-de Sitter Black HolesAug 17 1998Jan 18 1999We examine supersymmetry of four-dimensional asymptotically anti-de Sitter (AdS) dyonic black holes in the context of gauged N=2 supergravity. Our calculations concentrate on black holes with unusual topology and their rotating generalizations, but we ... More
Supersymmetric near-horizon geometry and Einstein-Cartan-Weyl spacesApr 07 2019We show that the horizon geometry for supersymmetric black hole solutions of minimal five-dimensional gauged supergravity is that of a particular Einstein-Cartan-Weyl (ECW) structure in three dimensions, involving the trace and traceless part of both ... More
Supersymmetric Godel-type Universe in four DimensionsOct 08 2003Dec 12 2003We generalize the classification of all supersymmetric solutions of pure N=2, D=4 gauged supergravity to the case when external sources are included. It is shown that the source must be an electrically charged dust. We give a particular solution to the ... More
M-Theory and Stringy Corrections to Anti-de Sitter Black Holes and Conformal Field TheoriesMar 09 1999Jul 07 1999We consider black holes in anti-de Sitter space AdS_{p+2} (p = 2,3,5), which have hyperbolic, flat or spherical event horizons. The $O(\alpha'^3)$ corrections (or the leading corrections in powers of the eleven-dimensional Planck length) to the black ... More
Supersymmetric gyratons in five dimensionsOct 11 2006Jan 29 2007We obtain the gravitational and electromagnetic field of a spinning radiation beam-pulse (a gyraton) in minimal five-dimensional gauged supergravity and show under which conditions the solution preserves part of the supersymmetry. The configurations represent ... More
Generalized instantons in N = 4 super Yang-Mills theory and spinorial geometryJul 23 2009Oct 12 2009Using spinorial geometry techniques, we classify the supersymmetric solutions of euclidean ${\cal N}=4$ super Yang-Mills theory. These backgrounds represent generalizations of instantons with nontrivial scalar fields turned on, and satisfy some constraints ... More
On the integrability of Einstein-Maxwell-(A)dS gravity in presence of Killing vectorsJun 30 2015Sep 09 2015We study some symmetry and integrability properties of four-dimensional Einstein-Maxwell gravity with nonvanishing cosmological constant in the presence of Killing vectors. First of all, we consider stationary spacetimes, which lead, after a timelike ... More
AdS$_5$ black strings in the stu model of FI-gauged $N=2$ supergravityMar 09 2018Oct 01 2018We analytically construct asymptotically AdS$_5$ black string solutions starting from the four-dimensional domain wall black hole of arXiv:0911.4926. It is shown that its uplift gives a black string in $d=5$ minimal gauged supergravity, with momentum ... More
Hairy black holes in N=2 gauged supergravityMay 12 2015May 22 2015We construct black holes with scalar hair in a wide class of four-dimensional N=2 Fayet-Iliopoulos gauged supergravity theories that are characterized by a prepotential containing one free parameter. Considering the truncated model in which only a single ... More
Conformal structure of the Schwarzschild black holeJun 06 2011Feb 25 2012We show that the scalar wave equation at low frequencies in the Schwarzschild geometry enjoys a hidden SL(2,R) invariance, which is not inherited from an underlying symmetry of the spacetime itself. Contrary to what happens for Kerr black holes, the vector ... More
Symplectically invariant flow equations for N=2, D=4 gauged supergravity with hypermultipletsFeb 03 2016Sep 13 2016We consider N=2 supergravity in four dimensions, coupled to an arbitrary number of vector- and hypermultiplets, where abelian isometries of the quaternionic hyperscalar target manifold are gauged. Using a static and spherically or hyperbolically symmetric ... More
Non(anti)commutative SuperspaceApr 23 2001Jun 04 2003We investigate the most general non(anti)commutative geometry in N=1 four-dimensional superspace, invariant under the classical (i.e., undeformed) supertranslation group. We find that a nontrivial non(anti)commutative superspace geometry compatible with ... More
w_{\infty} Algebras, Conformal Mechanics, and Black HolesOct 07 1999Feb 28 2000We discuss BPS solitons in gauged ${\cal N}=2$, D=4 supergravity. The solitons represent extremal black holes interpolating between different vacua of anti-de Sitter spaces. The isometry superalgebras are determined and the motion of a superparticle in ... More
Thermodynamics of Kerr-Newman-AdS Black Holes and Conformal Field TheoriesAug 03 1999Dec 06 1999We study the thermodynamics of four-dimensional Kerr-Newman-AdS black holes both in the canonical and the grand-canonical ensemble. The stability conditions are investigated, and the complete phase diagrams are obtained, which include the Hawking-Page ... More
Supersymmetric black holes and attractors in gauged supergravity with hypermultipletsMar 31 2015Apr 13 2015We consider four-dimensional $N=2$ supergravity coupled to vector- and hypermultiplets, where abelian isometries of the quaternionic K\"ahler hypermultiplet scalar manifold are gauged. Using the recipe given by Meessen and Ort\'{\i}n in arXiv:1204.0493, ... More
Black string first order flow in N=2, d=5 abelian gauged supergravityOct 24 2016Jan 16 2017We derive both BPS and non-BPS first-order flow equations for magnetically charged black strings in five-dimensional N=2 abelian gauged supergravity, using the Hamilton-Jacobi formalism. This is first done for the coupling to vector multiplets only and ... More
Black string first order flow in N=2, d=5 abelian gauged supergravityOct 24 2016We derive both BPS and non-BPS first-order flow equations for magnetically charged black strings in five-dimensional N=2 abelian gauged supergravity, using the Hamilton-Jacobi formalism. This is first done for the coupling to vector multiplets only and ... More
Duality invariance in Fayet-Iliopoulos gauged supergravityJun 16 2016Sep 13 2016We propose a geometric method to study the residual symmetries in $N=2$, $d=4$ $\text{U}(1)$ Fayet-Iliopoulos (FI) gauged supergravity. It essentially involves the stabilization of the symplectic vector of gauge couplings (FI parameters) under the action ... More
On the Geometry behind N=2 Supersymmetric Effective Actions in Four DimensionsMay 19 1997Jan 30 1998An introduction to Seiberg-Witten theory and its relation to theories which include gravity.
Dyonic AdS black holes from magnetohydrodynamicsDec 03 2008Jan 15 2009We use the AdS/CFT correspondence to argue that large dyonic black holes in anti-de Sitter spacetime are dual to stationary solutions of the equations of relativistic magnetohydrodynamics on the conformal boundary of AdS. The dyonic Kerr-Newman-AdS_4 ... More
Spinorial geometry, off-shell Killing spinor identities and higher derivative 5D supergravitiesJun 11 2018Aug 01 2018Killing spinor identities relate components of equations of motion to each other for supersymmetric backgrounds. The only input required is the field content and the supersymmetry transformations of the fields, as long as an on-shell supersymmetrization ... More
Embedding Diagrams of the N=2 Superconformal Algebra under Spectral FlowJun 09 2003Sep 04 2003The embedding diagrams of representations of the N=2 superconformal algebra with central charge c=3 are given. Some non-unitary representations possess subsingular vectors that are systematically described. The structure of the embedding diagrams is largely ... More
All timelike supersymmetric solutions of N=2, D=4 gauged supergravity coupled to abelian vector multipletsApr 01 2008The timelike supersymmetric solutions of N=2, D=4 gauged supergravity coupled to an arbitrary number of abelian vector multiplets are classified using spinorial geometry techniques. We show that the generalized holonomy group for vacua preserving N supersymmetries ... More
AdS_2 Supergravity and Superconformal Quantum MechanicsDec 09 2002Feb 19 2003We investigate the asymptotic dynamics of topological anti-de Sitter supergravity in two dimensions. Starting from the formulation as a BF theory, it is shown that the AdS_2 boundary conditions imply that the asymptotic symmetries form a super-Virasoro ... More
Rotating black holes in 4d gauged supergravityNov 07 2013Nov 24 2013We present new results towards the construction of the most general black hole solutions in four-dimensional Fayet-Iliopoulos gauged supergravities. In these theories black holes can be asymptotically AdS and have arbitrary mass, angular momentum, electric ... More
Surjectivity of Euler operators on temperate distributionsNov 11 2017Jul 11 2018Euler operators are partial differential operators of the form $P(\theta)$ where $P$ is a polynomial and $\theta_j = x_j \partial/\partial x_j$. We show that every non-trivial Euler operator is surjective on the space of temperate distributions on $R^d$. ... More
Hadamard operators on $\mathscr{D}'(\mathbb{R}^d)$Nov 27 2015May 24 2019We study continuous linear operators on $\mathscr{D}'(\mathbb{R}^d)$ which admit all monomials as eigenvectors, that is, operators of Hadamard type. Such operators on $C^\infty(\mathbb{R}^d)$ and on the space $A(\mathbb{R}^d)$ of real analytic functions ... More
BPS black holes in a non-homogeneous deformation of the stu model of $N=2$, $D=4$ gauged supergravityJul 20 2015We consider a deformation of the well-known stu model of $N=2$, $D=4$ supergravity, characterized by a non-homogeneous special K\"{a}hler manifold, and by the smallest electric-magnetic duality Lie algebra consistent with its upliftability to five dimensions. ... More
Nonlinear symmetries of black hole entropy in gauged supergravityJan 30 2017Freudenthal duality in N=2, D=4 ungauged supergravity is generated by an anti-involutive operator that acts on the electromagnetic fluxes, and results to be a symmetry of the Bekenstein-Hawking entropy. We show that, with a suitable extension, this duality ... More
Rotating black holes in the FI-gauged $N=2$, $D=4$ $\overline{\mathbb{C}\text{P}}^n$ modelFeb 08 2019Mar 25 2019We construct supersymmetric black holes with rotation or NUT charge for the $\overline{\mathbb{C}\text{P}}^n$- and the $\text{t}^3$ model of $N=2$, $D=4$ $\text{U}(1)$ FI-gauged supergravity. The solutions preserve 2 real supercharges, which are doubled ... More
Rotating black holes in the FI-gauged $N=2$, $D=4$ $\overline{\mathbb{C}\text{P}}^n$ modelFeb 08 2019We construct supersymmetric black holes with rotation or NUT charge for the $\overline{\mathbb{C}\text{P}}^n$- and the $\text{t}^3$ model of $N=2$, $D=4$ $\text{U}(1)$ FI-gauged supergravity. The solutions preserve 2 real supercharges, which are doubled ... More
The Asymptotic Dynamics of two-dimensional (anti-)de Sitter GravityFeb 12 2002Mar 06 2002We show that the asymptotic dynamics of two-dimensional de Sitter or anti-de Sitter Jackiw-Teitelboim (JT) gravity is described by a generalized two-particle Calogero-Sutherland model. This correspondence is established by formulating the JT model of ... More
Supersymmetric Domain Walls and Strings in D=5 gauged Supergravity coupled to Vector MultipletsFeb 27 2003Mar 21 2003We present new supersymmetric domain wall and string solutions of five-dimensional N = 2 gauged supergravity coupled to an arbitrary number of vector multiplets. Using the techniques of very special geometry allows to obtain the most general domain wall ... More
Chronology Protection in anti-de SitterNov 23 2004Jul 20 2005We consider 1/2 BPS excitations of AdS(5)xS(5) geometries in type IIB string theory that can be mapped into free fermion configurations according to the prescription of Lin, Lunin and Maldacena (LLM). It is shown that whenever the fermionic probability ... More
Asymptotic distribution of estimators in reduced rank regression settings when the regressors are integratedNov 07 2012In this paper the asymptotic distribution of estimators is derived in a general regression setting where rank restrictions on a submatrix of the coefficient matrix are imposed and the regressors can include stationary or I(1) processes. Such a setting ... More
A characteristic property of the space sApr 13 2013Jun 13 2013It is shown that under certain stability conditions a complemented subspace of the space $s$ of rapidly decreasing sequences is isomorphic to $s$ and this condition characterizes $s$. This result is used to show that for the classical Cantor set $X$ the ... More
Morley Finite Element Method for the Eigenvalues of the Biharmonic OperatorJun 11 2014Oct 27 2014This paper studies the nonconforming Morley finite element approximation of the eigenvalues of the biharmonic operator. A new $C^1$ conforming companion operator leads to an $L^2$ error estimate for the Morley finite element method which directly compares ... More
Data by Proxy -- Material Traces as Autographic VisualizationsJul 11 2019Information visualization limits itself, per definition, to the domain of symbolic information. This paper discusses arguments why the field should also consider forms of data that are not symbolically encoded, including physical traces and material indicators. ... More
Variational formulation and numerical analysis of linear elliptic equations in nondivergence form with Cordès coefficientsJun 17 2016Jul 13 2016In this paper, second-order elliptic partial differential equations in nondivergence form on convex domains are equivalently reformulated as variational fourth-order problems. This enables the use of standard finite element techniques for variational ... More
Uniqueness of Symplectic StructuresNov 13 2012Dec 12 2012This survey paper addresses uniqueness questions for symplectic forms on closed manifolds, explains what is known in several examples, and reviews some open problems.
Euler partial differential equations and Schwartz distributionsJun 03 2018Euler operators are partial differential operators of the form $P(\theta)$ where $P$ is a polynomial and $\theta_j = x_j \partial/\partial x_j$. They are surjective on the space of temperate distributions on $R^d$. We show that this is, in general, not ... More
Azimuthal asymmetries in Deeply Virtual Compton Scattering on an unpolarized proton targetOct 28 2008Nov 14 2008Preliminary results on azimuthal asymmetries in leptoproduction of real photons on an unpolarized hydrogen target measured at the HERMES experiment are presented. The analysis of data taken with different beam charges and helicities allows for a simultaneous ... More
Using Twitter to Model the EUR/USD Exchange RateFeb 07 2014Fast, global, and sensitively reacting to political, economic and social events of any kind, these are attributes that social media like Twitter share with foreign exchange markets. The leading assumption of this paper is that information which can be ... More
Modellvalidierung mit Hilfe von Quantil-Quantil-Plots unter Solvency II (Model validation on the basis of quantile-quantile-plots under Solvency II)Jul 27 2019Aug 01 2019After several years of development, the Solvency II-project has finally been set to work in the European Union with the beginning of the year 2016. This has caused massive changes in the regional legislative supervisory acts. One new aspect of regulation ... More
$\mathscr{E}'$ as an algebra by multiplicative convolutionSep 18 2015Jul 21 2018We study the algebra $\mathscr{E}'(\mathbb{R}^d)$ equipped with the multiplication $(T\star S)(f)=T_x(S_y(f(xy))$ where $xy=(x_1y_1,\dots,x_dy_d)$. This allows us a very elegant access to the theory of Hadamard type operators on $C^\infty(\Omega)$, $\Omega$ ... More
Hadamard operators on $\mathscr{D}'(\mathbb{R}^d)$Nov 27 2015We study continuous linear operators on $\mathscr{D}'(\mathbb{R}^d)$ which admit all monomials as eigenvectors, that is, operators of Hadamard type. Such operators on $C^\infty(\mathbb{R}^d)$ and on the space $A(\mathbb{R}^d)$ of real analytic functions ... More
Modellvalidierung mit Hilfe von Quantil-Quantil-Plots unter Solvency II (Model validation on the basis of quantile-quantile-plots under Solvency II)Jul 27 2019After several years of development, the Solvency II-project has finally been set to work in the European Union with the beginning of the year 2016. This has caused massive changes in the regional legislative supervisory acts. One new aspect of regulation ... More
Polynomial Functions on a Central RelationOct 09 2003We show that the algebra $\mathbf{R} = \bigl(R; \wedge, \veebar, 0, \bar{f}_i(x) (i \in I)\bigr)$ is central polynomially complete and finite.
Subfactors and planar algebrasApr 22 2003An inclusion of II$_1$ factors $N \subset M$ with finite Jones index gives rise to a powerful set of invariants that can be approached successfully in a number of different ways. We describe Jones' pictorial description of the standard invariant of a ... More
Topological Strings on Grassmannian Calabi-Yau manifoldsFeb 20 2008We present solutions for the higher genus topological string amplitudes on Calabi-Yau-manifolds, which are realized as complete intersections in Grassmannians. We solve the B-model by direct integration of the holomorphic anomaly equations using a finite ... More
Landau-Ginzburg String VacuaApr 20 1992We investigate a class of (2,2) supersymmetric string vacua which may be represented as Landau--Ginzburg theories with a quasihomogeneous potential which has an isolated singularity at the origin. There are at least three thousand distinct models in this ... More
Solving the Topological String on K3 FibrationsAug 04 2009We present solutions of the holomorphic anomaly equations for compact two-parameter Calabi-Yau manifolds which are hypersurfaces in weighted projective space. In particular we focus on K3-fibrations where due to heterotic type II duality the topological ... More
Boolean networks with veto functionsMay 14 2014Aug 27 2014Boolean networks are discrete dynamical systems for modeling regulation and signaling in living cells. We investigate a particular class of Boolean functions with inhibiting inputs exerting a veto (forced zero) on the output. We give analytical expressions ... More
Stability of Boolean and continuous dynamicsMar 23 2011Sep 29 2011Regulatory dynamics in biology is often described by continuous rate equations for continuously varying chemical concentrations. Binary discretization of state space and time leads to Boolean dynamics. In the latter, the dynamics has been called unstable ... More
Strong Coupling Singularities and Non-abelian Gauge Symmetries in $N=2$ String TheoryJan 05 1996Jan 21 1996We study a class of extremal transitions between topological distinct Calabi--Yau manifolds which have an interpretation in terms of the special massless states of a type II string compactification. In those cases where a dual heterotic description exists ... More
Chern-Simons formulation of three-dimensional gravity with torsion and nonmetricityJul 20 2005Jan 29 2007We consider various models of three-dimensional gravity with torsion or nonmetricity (metric affine gravity), and show that they can be written as Chern-Simons theories with suitable gauge groups. Using the groups ISO(2,1), SL(2,C) or SL(2,R) x SL(2,R), ... More
Seiberg-Witten theory and matrix modelsOct 28 2008May 13 2009We derive a family of matrix models which encode solutions to the Seiberg-Witten theory in 4 and 5 dimensions. Partition functions of these matrix models are equal to the corresponding Nekrasov partition functions, and their spectral curves are the Seiberg-Witten ... More
Swampland Distance Conjecture for One-Parameter Calabi-Yau ThreefoldsMar 02 2019We investigate the swampland distance conjecture (SDC) in the complex moduli space of type II compactifications on one-parameter Calabi-Yau threefolds. This class of manifolds contains hundreds of examples and, in particular, a subset of 14 geometries ... More
Comment on the Generation Number in Orbifold CompactificationsJul 31 1992There has been some confusion concerning the number of $(1,1)$-forms in orbifold compactifications of the heterotic string in numerous publications. In this note we point out the relevance of the underlying torus lattice on this number. We answer the ... More
Enumerative geometry of Calabi-Yau 4-foldsFeb 07 2007Gromov-Witten theory is used to define an enumerative geometry of curves in Calabi-Yau 4-folds. The main technique is to find exact solutions to moving multiple cover integrals. The resulting invariants are analogous to the BPS counts of Gopakumar and ... More
Counting BPS states on the Enriques Calabi-YauDec 19 2005Dec 15 2006We study topological string amplitudes for the FHSV model using various techniques. This model has a type II realization involving a Calabi-Yau threefold with Enriques fibres, which we call the Enriques Calabi-Yau. By applying heterotic/type IIA duality, ... More
Altruism in populations at the extinction transitionJun 10 2019We study the evolution of cooperation as a birth-death process in spatially extended populations. The benefit from the altruistic behavior of a cooperator is implemented by decreasing the death rate of its direct neighbours. The cost of cooperation is ... More
Impact of individual nodes in Boolean network dynamicsNov 22 2011Sep 13 2012Boolean networks serve as discrete models of regulation and signaling in biological cells. Identifying the key controllers of such processes is important for understanding the dynamical systems and planning further analysis. Here we quantify the dynamical ... More
Efficient exploration of discrete energy landscapesOct 14 2009Jan 18 2011Many physical and chemical processes, such as folding of biopolymers, are best described as dynamics on large combinatorial energy landscapes. A concise approximate description of dynamics is obtained by partitioning the micro-states of the landscape ... More
Regulatory networks and connected components of the neutral spaceApr 30 2009The functioning of a living cell is largely determined by the structure of its regulatory network, comprising non-linear interactions between regulatory genes. An important factor for the stability and evolvability of such regulatory systems is neutrality ... More
Black strings in AdS_5Aug 17 2007Jan 10 2008We present non-extremal magnetic black string solutions in five-dimensional gauged supergravity. The conformal infinity is the product of time and S^1xS_h, where S_h denotes a compact Riemann surface of genus h. The construction is based on both analytical ... More
Decision Support Systems - Technical Prerequisites and Military RequirementsNov 25 2010Decision Support Systems in the sense of online alternative course of action (ACAO) development and analysis as well as tools for online Development of Doctrine and Tactics Techniques, and Procedures (DTTP) for support to operations make it possible to ... More