arXiv subjects

A. Segui

Publications and source records attributed to A. Segui.

18 recordsLinked to original sources

arXiv2019

Stringy Dyonic Solutions and Clifford Structures

Using the toroidal compactification of string theory on n-dimensional tori, Tn, we investigate dyonic objects in arbitrary dimensions. First, we present a class of dyonic black solutions formed by two different D-branes using a correspondence between toroidal cycles and objects possessing both magnetic and electric charges, belonging to %%%% dyonic gauge symmetry. This symmetry could be associated with electrically charged magnetic monopole solutions in stringy model buildings of the standard model extensions. Then, we consider in some details such black hole classes obtained from even dimensional toroidal compactifications, and we find that they are linked to Cl(n) Clifford algebras using the vee product. It is believed that this analysis could be extended to dyonic objects which can be obtained from local Calabi-Yau manifold compactifications.

hep-th↗

arXiv2017

Four-qubit Systems and Dyonic Black Hole-Black Branes in Superstring Theory

Using dyonic solutions in the type IIA superstring theory on Calabi-Yau manifolds, we reconsider the study of black objects and quantum information theory using string/string duality in six dimensions. Concretely, we relate four-qubits with a stringy quaternionic moduli space of type IIA compactification associated with a dyonic black solution formed by black holes (BH) and black 2-branes (B2B) carrying 8 electric charges and 8 magnetic charges. This connection is made by associating the cohomology classes of the heterotic superstring on T^{4} to four-qubit states. These states are interpreted in terms of such dyonic charges resulting from the quaternionic symmetric space \frac{SO(4,4)}{SO(4)\times SO(4)} corresponding to a N=4 sigma model superpotential in two dimensions. The superpotential is considered as a functional depending on four quaternionic fields mapped to a class of Clifford algebras denoted as Cl_{0,4}. A link between such an algebra and the cohomology classes of T^4 in heterotic superstring theory is also given.

hep-th↗

arXiv2016

Qubit and Fermionic Fock Spaces from Type II Superstring Black Holes

Using Hodge diagram combinatorial data, we study qubit and fermionic Fock spaces from the point of view of type II superstring black holes based on complex compactifications. Concretely, we establish a one-to-one correspondence between qubits, fermionic spaces and extremal black holes in maximally supersymmetric supergravity obtained from type II superstring on complex toroidal and Calabi-Yau compactifications. We interpret the differential forms of the n-dimensional complex toroidal compactification as states of n-qubits encoding information on extremal black hole charges. We show that there are 2^n copies of n-qubit systems which can be split as 2^n=2^{n-1}+2^{n-1}. More precisely, 2^{n-1} copies are associated with even D-brane charges in type IIA superstring and the other 2^{n-1} ones correspond to odd D-brane charges in IIB superstring. This correspondence is generalized to a class of Calabi-Yau manifolds. In connection with black hole charges in type IIA superstring, an n-qubit system has been obtained from a canonical line bundle of n factors of one dimensional projective space \mathbb{CP}^1.

hep-th↗

arXiv2015

Qubits from Adinkra Graph Theory via Colored Toric Geometry

We develop a new approach to deal with qubit information systems using toric geometry and its relation to Adinkra graph theory. More precisely, we link three different subjects namely toric geometry, Adinkras and quantum information theory. This one to one correspondence may be explored to attack qubit system problems using geometry considered as a powerful tool to understand modern physics including string theory. Concretely, we examine in some details the cases of one, two, and three qubits, and we find that they are associated with \bf CP^1, \bf CP^1\times CP^1 and \bf CP^1\times CP^1\times CP^1 toric varieties respectively. Using a geometric procedure referred to as colored toric geometry, we show that the qubit physics can be converted into a scenario handling toric data of such manifolds by help of Adinkra graph theory. Operations on toric information can produce universal quantum gates.

hep-th↗

arXiv2015

On Heat Properties of AdS Black Holes in Higher Dimensions

We investigate the heat properties of AdS Black Holes in higher dimensions. We consider the study of the corresponding thermodynamical properties including the heat capacity explored in the determination of the black hole stability. In particular, we compute the heat latent. To overcome the instability problem, the Maxwell construction, in the (T,S)-plane, is elaborated. This method is used to modify the the Hawking-Page phase structure by removing the negative heat capacity regions. Then, we discuss the thermodynamic cycle and the heat engines using the way based on the extraction of the work from a black hole solution.

hep-th↗

arXiv2013

On Thermodynamics of 2d Black Holes in Brane Inflationary Potentials

Inspired from the inflation brane world cosmology, we study the thermodynamics of a black hole solution in two dimensional dilaton gravity with an arctangent potential background. We first derive the two dimensional black hole geometry, then we examine its asymptotic behaviors. More precisely, we find that such behaviors exhibit properties appearing in some known cases including the Anti de Sitter and the Schwarzchild black holes. Using the complex path method, we compute the Hawking radiation. The entropy function can be related to the value of the potential at the horizon.

hep-th↗

arXiv2012

On Mass Gap in Type IIB Quantum Hall Solitons

We discuss the mass gap in quantum Hall solitons (QHS) embedded in superstring theory. In particular, we give two holographic models which are obtained from D-brane configurations in type IIB superstring compactifications. The first one deals with the monolayered system in the D3/D7 brane set up. The second model corresponds to a multilayered system which is described by intersecting D5-branes wrapping a particular set of 3-cycles. In both models, we have shown that the mass gap is related to the filling factor.

hep-th↗

arXiv2010

Brane Realizations of Quantum Hall Solitons and Kac-Moody Lie Algebras

Using quiver gauge theories in (1+2)-dimensions, we give brane realizations of a class of Quantum Hall Solitons (QHS) embedded in Type IIA superstring on the ALE spaces with exotic singularities. These systems are obtained by considering two sets of wrapped D4-branes on 2-spheres. The space-time on which the QHS live is identified with the world-volume of D4-branes wrapped on a collection of intersecting 2-spheres arranged as extended Dynkin diagrams of Kac-Moody Lie algebras. The magnetic source is given by an extra orthogonal D4-brane wrapping a generic 2-cycle in the ALE spaces. It is shown as well that data on the representations of Kac-Moody Lie algebras fix the filling factor of the QHS. In case of finite Dynkin diagrams, we recover results on QHS with integer and fractional filling factors known in the literature. In case of hyperbolic bilayer models, we obtain amongst others filling factors describing holes in the graphene.

hep-th↗

arXiv2010

Embedding Fractional Quantum Hall Solitons in M-theory Compactifications

We engineer U(1)^n Chern-Simons type theories describing fractional quantum Hall solitons (QHS) in 1+2 dimensions from M-theory compactified on eight dimensional hyper-K\"{a}hler manifolds as target space of N=4 sigma model. Based on M-theory/Type IIA duality, the systems can be modeled by considering D6-branes wrapping intersecting Hirzebruch surfaces F_0's arranged as ADE Dynkin Diagrams and interacting with higher dimensional R-R gauge fields. In the case of finite Dynkin quivers, we recover well known values of the filling factor observed experimentally including Laughlin, Haldane and Jain series.

hep-th↗

arXiv2008

The Supermembrane with Central Charges on a G2 Manifold

We construct the 11D supermembrane with topological central charges induced through an irreducible winding on a G2 manifold realized from the T7/Z2xZ2xZ2 orbifold construction. The hamiltonian H of the theory on a T7 target has a discrete spectrum. Within the discrete symmetries of H associated to large diffeomorphisms, the Z2xZ2xZ2 group of automorphisms of the quaternionic subspaces preserving the octonionic structure is relevant. By performing the corresponding identification on the target space, the supermembrane may be formulated on a G2 manifold, preserving the discretness of its supersymmetric spectrum. The corresponding 4D low energy effective field theory has N=1 supersymmetry.

hep-th↗

arXiv2008

Entropy of Pairs of Dual Attractors in 6D/7D

We study the attractor mechanism of dual pairs of black brane bounds in N=2 supergravity in six and seven dimensions. First, we consider the effective potentials of the 6D and 7D black branes as well as their entropies. The contribution coming from the SO(1,1) factor of the moduli spaces M_{6D} and M_{7D} of these theories is carefully analyzed and it is used to motivate the study of the dual black branes bounds; which in turn allow to fix the critical value of the dilaton at horizon. The attractor eqs of the black branes and the bound pairs are derived by combining the criticality conditions of the corresponding effective potentials and the Lagrange multiplier method capturing constraints eqs on the fields moduli.

hep-th↗

arXiv2008

N=2 Supersymmetric Black Attractors in Six and Seven Dimensions

Using a quaternionic formulation of the moduli space $\boldsymbol{M}({\small IIA/K3}) $ of 10D type IIA superstring on a generic K3 complex surface with volume $\boldsymbol{V}_{0}$, we study extremal $\mathcal{N}=2$ black attractors in 6D space-time and their uplifting to 7D. For the 6D theory, we exhibit the role played by 6D $\mathcal{N}=1$ hypermultiplets and the $Z^{m}$ central charges isotriplet of the 6D $\mathcal{N}=2$ superalgebra. We construct explicitly the special hyperKahler geometry of $% \boldsymbol{M}({\small IIA/K3}) $ and show that the $SO(4) \times SO(20) $ invariant hyperKahler potential is given by $\mathcal{H}=\mathcal{H}_{0}+\mathrm{Tr}[ \ln (1-% \boldsymbol{V}_{0}^{-1}\boldsymbol{S}) ] $ with Kahler leading term $\mathcal{H}_{0}=\mathrm{Tr}[ \ln \boldsymbol{V}_{0}] $ plus an extra term which can be expanded as a power series in $\boldsymbol{V}%_{0}^{-1}$ and the traceless and symmetric 3$\times $3 matrix $\boldsymbol{S} $. We also derive the holomorphic matrix prepotential $\mathcal{G}$ and the flux potential $\mathcal{G}_{BH}$ of the 6D black objects induced by the topology of the RR field strengths $\mathcal{F}_{2}=d\mathcal{A}_{1}$ and $% \mathcal{F}_{4}=d\mathcal{A}_{3}$ on the K3 surface and show that $\mathcal{G% }_{BH}$ reads as $Q_{0}+\sum_{m=1}^{3}q^{m}Z^{m}$. Moreover, we reveal that $% Z^{m}=\sum_{I=1}^{20}Q_{I}(\int_{C_{2}^{I}}J^{m}) $ where the isotriplet $J^{m}$ is the hyperKahler 2- form on the K3 surface. It is found as well that the uplifting to seven dimensions is quite similar to 4D/5D correspondence for back hole potential considered in arXiv 0707.0964 [hep-th].

hep-th↗

arXiv2005

A fluid of black holes at the beginning of the Universe

The most entropic fluid can be related to a dense gas of black holes that we use to study the beginning of the universe. We encounter difficulties to compatibilize an adiabatic expansion with the growing area for the coalescence of black holes. This problem may be circumvented for a quantum black hole fluid, whose classical counterpart can be described by a percolating process at the critical point. This classical regime might be related to the energy content of the current universe.

hep-th↗

arXiv2005

The initial conditions of the Universe and holography

We address the initial conditions for an expanding cosmology using the holographic principle. For the case of a closed model, the old prescription of Fishler and Susskind, that uses the particle horizon to encode the bulk degrees of freedom, can be implemented for accelerated models with enough acceleration. As a bonus we have singularity free bouncing models. The bound is saturated for co-dimension one branes dominated universes.

gr-qc↗

arXiv2005

Holographic Cosmology and Uncertainty Relation

It is believed that a primary principle of the theory of quantum gravity is the Holographic Principle according to which a physical system can be described only by degrees of freedom living on its boundary. The generalized covariant formulation of the principle considers the entropy content on truncated light-sheets: light-like hypersurfaces of non-positive expansion orthogonally generated from a boundary. When we construct the truncated light-sheets for cosmological observers we find a general expression for the minimum cosmic time interval from the apparent horizon to verify the holographic prescription; this minimum time is related to quantum effects involved in the entropy computation. Finally, we arrive to the uncertainty relation from the Holographic Principle, which suggests a deep connection between general covariance, entropy bounds and quantum mechanics.

gr-qc↗

arXiv2004

A toy model for the coincidence problem

The measured values of the matter energy density and the vacuum energy density are obtained using an adiabatic black hole percolating model at the critical point. The percolation of black holes is related with an expanding isotropic universe filled with the most entropic fluid saturating the holographic bound.

gr-qc↗

arXiv2003

Problems and cures (partial) for holographic cosmology

We analyze the validity of the generalized covariant entropy bound near the apparent horizon of isotropic expanding cosmological models. We encounter violations of the bound for cosmic times smaller than a threshold. By introducing an infrared cutoff we are able to mantain the bound for a radiation dominated universe. We study different physical mechanisms to restore the bound, as a non-additivity of the entropy at a fundamental level and/or a cosmological uncertainty relation.

hep-th↗

arXiv1995

Spectroscopy and large scale wave functions

We discuss the relevance of long wavelength excitations for the low energy spectrum of QCD, and try to develop an efficient method for solving the Schrodinger equation, and for extracting the glueball masses and long wavelength functions of the ground and excited states. Some technical problems appearing in the calculations of SU(3) gauge theory are discussed.

hep-ph↗