Advanced search    

Search: authors:"Stefanos Katmadas"

18 papers found.
Use AND, OR, NOT, +word, -word, "long phrase", (parentheses) to fine-tune your search.

Bolting multicenter solutions

We introduce a solvable system of equations that describes non-extremal multicenter solutions to six-dimensional ungauged supergravity coupled to tensor multiplets. The system involves a set of functions on a three-dimensional base metric. We obtain a family of non-extremal axisymmetric solutions that generalize the known multicenter extremal solutions, using a particular base ...

AdS4 black holes from M-theory

We consider the BPS conditions of eleven dimensional supergravity, restricted to an appropriate ansatz for black holes in four non-compact directions. Assuming the internal directions to be described by a circle fibration over a Kähler manifold and considering the case where the complex structure moduli are frozen, we recast the resulting flow equations in terms of polyforms on ...

Higher derivative corrections to BPS black hole attractors in 4d gauged supergravity

We analyze BPS black hole attractors in 4d gauged supergravity in the presence of higher derivative supersymmetric terms, including a Weyl-squared-type action, and determine the resulting corrections to the Bekenstein-Hawking entropy. The near-horizon geometry AdS2×S2 (or other Riemann surface) preserves half of the supercharges in N = 2 supergravity with Fayet-Iliopoulos gauging. ...

Static BPS black holes in U(1) gauged supergravity

Stefanos Katmadas 0 0 Dipartimento di Fisica, Universit`a di Milano-Bicocca , I-20126 Milano, Italy INFN, sezione di Milano-Bicocca, Milano, Italy We consider the flow equations for 1/4-BPS

Floating JMaRT

We define a new partially solvable system of equations that parametrises solutions to six-dimensional \( \mathcal{N}=\left(1,\ 0\right) \) ungauged supergravity coupled to tensor multiplets. We obtain this system by applying a series of dualities on the known floating brane system, imposing that it allows for the JMaRT solution. We construct an explicit multi-centre solution ...

The off-shell c-map

The off-shell version of the c-map is presented, based on a systematic off-shell reduction from four to three space-time dimensions for supergravity theories with eight supercharges. In the reduction, the R-symmetry group is enhanced to local \( \left[\mathrm{S}\mathrm{U}(2)\times \mathrm{S}\mathrm{U}(2)\right]/{\mathbb{Z}}_2=\mathrm{SO}(4) \) and the c-map is effected by a parity ...

Wilson lines for AdS5 black strings

We describe a simple method of extending AdS5 black string solutions of 5d gauged supergravity in a supersymmetric way by addition of Wilson lines along a circular direction in space. When this direction is chosen along the string, and due to the specific form of 5d supergravity that features Chern-Simons terms, the existence of magnetic charges automatically generates conserved ...

Non-BPS multi-bubble microstate geometries

We construct the first smooth horizonless supergravity solutions that have two topologically-nontrivial three-cycles supported by flux, and that have the same mass and charges as a non-extremal D1-D5-P black hole. Our configurations are solutions to six-dimensional ungauged supergravity coupled to a tensor multiplet, and uplift to solutions of Type IIB supergravity. The solutions ...

A bubbling bolt

We present a new solvable system, solving the equations of five-dimensional ungauged \( \mathcal{N} \) = 1 supergravity coupled to vector multiplets, that allows for non-extremal solutions and reduces to a known system when restricted to the floating brane Ansatz. A two-centre globally hyperbolic smooth geometry is obtained as a solution to this system, describing a bubble linking ...

\( \mathcal{N} \) = 2 higher-derivative couplings from strings

Stefanos Katmadas 1 Ruben Minasian 0 0 Institut de Physique Theorique , CEA Saclay, CNRS URA 2306 , F-91191 Gif-sur-Yvette, France 1 Dipartimento di Fisica, Universit`a di Milano-Bicocca , I-20126

Non-BPS walls of marginal stability

Guillaume Bossard 1 Stefanos Katmadas 1 0 Institut de Physique Tehorique , CEA Saclay, CNRS-URA 2306, 91191 Gif sur Yvette, France 1 Centre de Physique Tehorique , Ecole Polytechnique, CNRS, 91128

Duality covariant multi-centre black hole systems

We present a manifestly duality covariant formulation of the composite nonBPS and almost-BPS systems of multi-centre black hole solutions in four dimensions. The method of nilpotent orbits is used to define the two systems in terms of first order flow equations that transform covariantly under the duality group. Subsequently, we rewrite both systems of equations in terms of real, ...

Duality covariant non-BPS first order systems

Guillaume Bossard 0 Stefanos Katmadas 0 0 Centre de Physique Theorique , E We study extremal black hole solutions to four dimensional N = 2 supergravity based on a cubic symmetric scalar manifold

Ungauging black holes and hidden supercharges

We embed the general solution for non-BPS extremal asymptotically flat static and under-rotating black holes in abelian gauged D = 4 \( \mathcal{N}=2 \) supergravity, in the limit where the scalar potential vanishes but the gauging does not. Using this result, we show explicitly that some supersymmetries are preserved in the near horizon region of all the asymptotically flat ...

The off-shell 4D/5D connection

A systematic off-shell reduction scheme from five to four space-time dimensions is presented for supergravity theories with eight supercharges. It is applicable to theories with higher-derivative couplings and it is used to address a number of open questions regarding BPS black holes in five dimensions. Under this reduction the 5D Weyl multiplet becomes reducible and decomposes ...

Near-horizon analysis of D=5 BPS black holes and rings

A comprehensive analysis is presented based exclusively on near-horizon data to determine the attractor equations and the entropy of BPS black holes and rings in five space-time dimensions, for a Lagrangian invariant under eight supersymmetries with higher-derivative couplings. For spinning black holes the results only partially agree with the results of previous work, where often ...

First-order flows and stabilisation equations for non-BPS extremal black holes

We derive a generalised form of flow equations for extremal static and rotating non-BPS black holes in four-dimensional ungauged N = 2 supergravity coupled to vector multiplets. For particular charge vectors, we give stabilisation equations for the scalars, analogous to the BPS case, describing full known solutions. Based on this, we propose a generic ansatz for the stabilisation ...

New supersymmetric higher-derivative couplings: full N = 2 superspace does not count!

An extended class of N = 2 locally supersymmetric invariants with higher-derivative couplings based on full superspace integrals, i s constructed. These invariants may depend on unrestricted chiral supermultiplets, on vect or supermultiplets and on the Weyl supermultiplet. Supersymmetry is realized off-shell. A non-renormalization theorem is proven according to which none of these ...