scholarly journals ADAMS-IWASAWA $\mathcal{N} = 8$ BLACK HOLES

2012 ◽  
Vol 13 ◽  
pp. 44-53 ◽  
Author(s):  
SERGIO LUIGI CACCIATORI ◽  
BIANCA LETIZIA CERCHIAI ◽  
ALESSIO MARRANI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Symmetric Space ◽  
Lie Algebra ◽  
Lie Group ◽  
Cartan Subalgebra ◽  
Discrete Subgroup ◽  
Iwasawa Decomposition ◽  
Extremal Black Hole ◽  
Supergravity Theory

We study some of the properties of the geometry of the exceptional Lie group E7(7), which describes the U-duality of the [Formula: see text], d = 4 supergravity. In particular, based on a symplectic construction of the Lie algebra 𝔢7(7) due to Adams, we compute the Iwasawa decomposition of the symmetric space [Formula: see text], which gives the vector multiplets' scalar manifold of the corresponding supergravity theory. The explicit expression of the Lie algebra is then used to analyze the origin of [Formula: see text] as scalar configuration of the "large" ⅛-BPS extremal black hole attractors. In this framework it turns out that the U(1) symmetry spanning such attractors is broken down to a discrete subgroup ℤ4, spoiling their dyonic nature near the origin of the scalar manifold. This is a consequence of the fact that the maximal manifest off-shell symmetry of the Iwasawa parametrization is determined by a completely non-compact Cartan subalgebra of the maximal subgroup SL(8, ℝ) of E7(7), which breaks down the maximal possible covariance SL(8, ℝ) to a smaller SL(7, ℝ) subgroup. These results are compared with the ones obtained in other known bases, such as the Sezgin-van Nieuwenhuizen and the Cremmer-Julia /de Wit-Nicolai frames.

scholarly journals The statistical mechanics of near-extremal black holes

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Luca V. Iliesiu ◽  
Gustavo J. Turiaci
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Partition Function ◽  
Gauge Field ◽  
Dimensional Reduction ◽  
Degrees Of Freedom ◽  
Energy Scale ◽  
Fixed Charge ◽  
Extremal Black Hole ◽  
Extremal Black Holes

Abstract An important open question in black hole thermodynamics is about the existence of a “mass gap” between an extremal black hole and the lightest near-extremal state within a sector of fixed charge. In this paper, we reliably compute the partition function of Reissner-Nordström near-extremal black holes at temperature scales comparable to the conjectured gap. We find that the density of states at fixed charge does not exhibit a gap; rather, at the expected gap energy scale, we see a continuum of states. We compute the partition function in the canonical and grand canonical ensembles, keeping track of all the fields appearing through a dimensional reduction on S2 in the near-horizon region. Our calculation shows that the relevant degrees of freedom at low temperatures are those of 2d Jackiw-Teitelboim gravity coupled to the electromagnetic U(1) gauge field and to an SO(3) gauge field generated by the dimensional reduction.

scholarly journals EXTREMAL BLACK HOLES AND ELEMENTARY STRING STATES

1995 ◽  
Vol 10 (28) ◽  
pp. 2081-2093 ◽  
Author(s):  
ASHOKE SEN
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Entropy ◽  
Extremal Black Hole ◽  
Coupling Constant ◽  
Left Handed ◽  
Quantum Numbers ◽  
Independent Parameters ◽  
Elementary String ◽  
Extremal Black Holes

Some of the extremal black hole solutions in string theory have the same quantum numbers as the Bogomol’nyi saturated elementary string states. We explore the possibility that these black holes can be identified with elementary string excitations. It is shown that stringy effects could correct the Bekenstein-Hawking formula for the black hole entropy in such a way that it correctly reproduces the logarithm of the density of elementary string states. In particular, this entropy has the correct dependence on three independent parameters, the mass and the left-handed charge of the black hole, and the string coupling constant.

Characteristic functions of semigroups in semi-simple Lie groups

2019 ◽  
Vol 31 (4) ◽  
pp. 815-842
Author(s):  
Luiz A. B. San Martin ◽  
Laercio J. Santos
Keyword(s):  
Laplace Transform ◽  
Lie Groups ◽  
Lie Algebra ◽  
Lie Group ◽  
Convex Cone ◽  
Convex Set ◽  
Flag Manifold ◽  
Riemannian Metric ◽  
Iwasawa Decomposition ◽  
Characteristic Functions

Abstract Let G be a noncompact semi-simple Lie group with Iwasawa decomposition {G=KAN} . For a semigroup {S\subset G} with nonempty interior we find a domain of convergence of the Helgason–Laplace transform {I_{S}(\lambda,u)=\int_{S}e^{\lambda(\mathsf{a}(g,u))}\,dg} , where dg is the Haar measure of G, {u\in K} , {\lambda\in\mathfrak{a}^{\ast}} , {\mathfrak{a}} is the Lie algebra of A and {gu=ke^{\mathsf{a}(g,u)}n\in KAN} . The domain is given in terms of a flag manifold of G written {\mathbb{F}_{\Theta(S)}} called the flag type of S, where {\Theta(S)} is a subset of the simple system of roots. It is proved that {I_{S}(\lambda,u)<\infty} if λ belongs to a convex cone defined from {\Theta(S)} and {u\in\pi^{-1}(\mathcal{D}_{\Theta(S)}(S))} , where {\mathcal{D}_{\Theta(S)}(S)\subset\mathbb{F}_{\Theta(S)}} is a B-convex set and {\pi:K\rightarrow\mathbb{F}_{\Theta(S)}} is the natural projection. We prove differentiability of {I_{S}(\lambda,u)} and apply the results to construct of a Riemannian metric in {\mathcal{D}_{\Theta(S)}(S)} invariant by the group {S\cap S^{-1}} of units of S.

scholarly journals Distributions of extremal black holes in Calabi-Yau compactifications

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
George Hulsey ◽  
Shamit Kachru ◽  
Sungyeon Yang ◽  
Max Zimet
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Moduli Space ◽  
Black Hole Horizon ◽  
Extremal Black Hole ◽  
Vector Multiplet ◽  
Horizon Area ◽  
Extremal Black Holes

Abstract We study non-supersymmetric extremal black hole excitations of 4d $$ \mathcal{N} $$ N = 2 supersymmetric string vacua arising from compactification on Calabi-Yau threefolds. The values of the (vector multiplet) moduli at the black hole horizon are governed by the attractor mechanism. This raises natural questions, such as “what is the distribution of attractor points on moduli space?” and “how many attractor black holes are there with horizon area up to a certain size?” We employ tools developed by Denef and Douglas [1] to answer these questions.

scholarly journals EXTREMAL BLACK HOLES, HOLOGRAPHY AND COARSE GRAINING

2011 ◽  
Vol 26 (12) ◽  
pp. 1903-1971 ◽  
Author(s):  
JOAN SIMON
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Recent Progress ◽  
Coarse Graining ◽  
Extremal Black Hole ◽  
Holographic Screens ◽  
Dynamical Description ◽  
Gravitational Thermodynamics ◽  
Extremal Black Holes

I review some of the concepts at the crossroads of gravitational thermodynamics, holography and quantum mechanics. First, the origin of gravitational thermodynamics due to coarse graining of quantum information is exemplified using the half-BPS sector of [Formula: see text] SYM and its LLM description in type IIB supergravity. The notion of black holes as effective geometries, its relation to the fuzzball programme and some of the puzzles raising for large black holes are discussed. Second, I review recent progress for extremal black holes, both microscopically, discussing a constituent model for stationary extremal non-BPS black holes, and semiclassically, discussing the extremal black hole/CFT conjecture. The latter is examined from the AdS3/CFT2 perspective. Third, I review the importance of the holographic principle to encode nonlocal gravity features allowing us to relate the gravitational physics of local observers with thermodynamics and the role causality plays in these arguments by identifying horizons (screens) as diathermic walls. I speculate with the emergence of an approximate CFT in the deep IR close to any horizon and its relation with an effective dynamical description of the degrees of freedom living on these holographic screens.

scholarly journals ENTROPY OF EXTREMAL DYONIC BLACK HOLES

1996 ◽  
Vol 11 (37) ◽  
pp. 2933-2939 ◽  
Author(s):  
A. GHOSH ◽  
P. MITRA
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Extremal Black Hole ◽  
Classical Action ◽  
Charged Black Holes ◽  
Thermodynamic Entropy ◽  
Black Hole Solutions

For extremal charged black holes, the thermodynamic entropy is proportional to the mass or charges but not proportional to the area. This is demonstrated here for dyonic extremal black hole solutions of string theory. It is pointed out that these solutions have zero classical action although the area is nonzero. By combining the general form of the entropy allowed by thermodynamics with recent observations in the literature it is possible to fix the entropy almost completely.

scholarly journals Asymptotically Lifshitz black hole solutions in F(R) gravity

2014 ◽  
Vol 92 (1) ◽  
pp. 76-81 ◽  
Author(s):  
S.H. Hendi ◽  
B. Eslam Panah ◽  
C. Corda
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Symmetric Space ◽  
Invariant Theory ◽  
Matter Field ◽  
Spherically Symmetric ◽  
Pure Gravity ◽  
Lifshitz Black Holes ◽  
Lifshitz Black Hole ◽  
Black Hole Solutions

We consider a class of spherically symmetric space–time to obtain some interesting solutions in F(R) gravity without matter field (pure gravity). We investigate the geometry of the solutions and find that there is an essential singularity at the origin. In addition, we show that there is an analogy between obtained solutions with the black holes of Einstein-Λ-power Maxwell invariant theory. Furthermore, we find that these solutions are equivalent to the asymptotically Lifshitz black holes. Also, we calculate d2F/dR2 to examine the Dolgov–Kawasaki stability criterion.

scholarly journals Black holes with topological charges in Chern-Simons AdS5 supergravity

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Laura Andrianopoli ◽  
Gaston Giribet ◽  
Darío López Díaz ◽  
Olivera Miskovic
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hamiltonian Formalism ◽  
Naked Singularity ◽  
Extremal Black Hole ◽  
Pure Gauge ◽  
Static Black Hole ◽  
Abelian Field ◽  
Chern Simons ◽  
Spatial Section

Abstract We study static black hole solutions with locally spherical horizons coupled to non-Abelian field in $$ \mathcal{N} $$ N = 4 Chern-Simons AdS5 supergravity. They are governed by three parameters associated to the mass, axial torsion and amplitude of the internal soliton, and two ones to the gravitational hair. They describe geometries that can be a global AdS space, naked singularity or a (non-)extremal black hole. We analyze physical properties of two inequivalent asymptotically AdS solutions when the spatial section at radial infinity is either a 3-sphere or a projective 3-space. An important feature of these 3-parametric solutions is that they possess a topological structure including two SU(2) solitons that wind nontrivially around the black hole horizon, as characterized by the Pontryagin index. In the extremal black hole limit, the solitons’ strengths match and a soliton-antisoliton system unwinds. That limit admits both non-BPS and BPS configurations. For the latter, the pure gauge and non-pure gauge solutions preserve 1/2 and 1/16 of the original supersymmetries, respectively. In a general case, we compute conserved charges in Hamiltonian formalism, finding many similarities with standard supergravity black holes.

scholarly journals Timelike geodesics around a charged spherically symmetric dilaton black hole

2015 ◽  
pp. 41-48 ◽  
Author(s):  
C. Blaga
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Test Particle ◽  
Effective Potential ◽  
Equations Of Motion ◽  
Equation Of Motion ◽  
Qualitative Approach ◽  
Extremal Black Hole ◽  
Spherically Symmetric ◽  
Dilaton Black Hole

In this paper we study the timelike geodesics around a spherically symmetric charged dilaton black hole. The trajectories around the black hole are classified using the effective potential of a free test particle. This qualitative approach enables us to determine the type of orbit described by test particle without solving the equations of motion, if the parameters of the black hole and the particle are known. The connections between these parameters and the type of orbit described by the particle are obtained. To visualize the orbits we solve numerically the equation of motion for different values of parameters envolved in our analysis. The effective potential of a free test particle looks different for a non-extremal and an extremal black hole, therefore we have examined separately these two types of black holes.

scholarly journals Topological stars, black holes and generalized charged Weyl solutions

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Ibrahima Bah ◽  
Pierre Heidmann
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Closed Form ◽  
Extremal Black Hole ◽  
Four Dimensions ◽  
Black Strings ◽  
Type Iib String Theory ◽  
Multi Body

Abstract We construct smooth static bubble solutions, denoted as topological stars, in five-dimensional Einstein-Maxwell theories which are asymptotic to ℝ1,3×S1. The bubbles are supported by allowing electromagnetic fluxes to wrap smooth topological cycles. The solutions live in the same regime as non-extremal static charged black strings, that reduce to black holes in four dimensions. We generalize to multi-body configurations on a line by constructing closed-form generalized charged Weyl solutions in the same theory. Generic solutions consist of topological stars and black strings stacked on a line, that are wrapped by electromagnetic fluxes. We embed the solutions in type IIB String Theory on S1×T4. In this framework, the charged Weyl solutions provide a novel class in String Theory of multiple charged objects in the non-supersymmetric and non-extremal black hole regime.

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