arXiv subjects

L. B Drissi

Publications and source records attributed to L. B Drissi.

18 recordsLinked to original sources

arXiv2025

Landscape of Narain CFTs

In this work, we investigate the AdS$_{3}$ gravitational bulk dual to an ensemble of Narain CFTs and their generalisations to establish bounds consistent with the Swampland program. Focusing on the AdS distance and finiteness conjectures, we show that the central charge of Narain CFTs forming the ensemble must be finite. Combining anomaly and unitary requirements, we derive an upper bound on the rank of the abelian U(1) gauge symmetries that can consistently couple to the AdS$_{3}$ gravity. We give explicit realisations of these constraints by determining the range of the Chern-Simons level $k^{G}$ corresponding to a bounded AdS$_{3}$ radius$.$ Accordingly, the Narain landscape is finite with a number of admissible CFTs constrained as $3/2\lesssim c\lesssim 10^{3}.$

hep-th↗

arXiv2025

Fluctuating Ensemble Averages and the BTZ Threshold

Recent work shows fascinating links between ensemble averaging and the Swampland program. In order to break the emerging global symmetries of the ensemble averaging as dictated by the no global symmetries conjecture, one may consider fluctuations away from the average given by deviations in the Siegel-Weil formula. In this work, we investigate the physical interpretation of these fluctuations in the bulk physics and pinpoint the states giving rise to them. For this purpose, we explore an ensemble of generalised Narain CFTs and build the AdS$_{3}$ gravitational dual in the Chern-Simons (CS) framework. We study the associated charged BTZ black hole solution and assess its stability. Using the Swampland weak gravity conjecture, we show that the fluctuations of the ensemble average are below the BTZ threshold and correspond to a sublattice of superextremal states emitted by the black hole. We exploit the logarithmic density of states to derive bounds on the charged vectors of the abelian CS symmetry and introduce a novel formulation of the density function to ensure consistency with the sublattice WGC. We establish bounds that allows to distinguish heavy states contributing to the average from light states generating fluctuations around it.

hep-th↗

arXiv2024

Finiteness of 3D higher spin gravity Landscape

We give Swampland constraints on the three dimensional Landscape of Anti-de Sitter higher spin gravity in the Chern-Simons formulation with connection valued in various split real forms of Lie algebras. We derive the finiteness conjecture by computing the upper bound on the rank of possible gauge groups then we refine it using the AdS distance conjecture. We discuss the implications of this Swampland constraint on the spectrum of higher spin gravity theories and we compare it with the gravitational exclusion principle required from BTZ black hole consideration to excerpt a constraint on the Chern-Simons level k.

hep-th↗

arXiv2023

Embedding Integrable Superspin Chain in String Theory

Using results on topological line defects of 4D Chern-Simons theory and the algebra/cycle homology correspondence in complex surfaces $\mathcal{S}$ with ADE singularities, we study the graded properties of the $sl(m|n)$ chain and its embedding in string theory. Because of the $\mathbb{Z}_{2}$-grading of $ sl(m|n)$, we show that the $\left( m+n\right) !/m!n!$ varieties of superspin chains with underlying super geometries have different cycle homologies. We investigate the algebraic and homological features of these integrable quantum chains and give a link between graded 2-cycles and genus-g Rieman surfaces $Σ_{g}$. Moreover, using homology language, we yield the brane realisation of the $sl(m|n)$ chain in type IIA string and its uplift to M-theory. Other \textrm{aspects} like graded complex surfaces with $sl(m|n)$ singularity as well as super magnons are also described.

hep-th↗

arXiv2023

't Hooft lines of ADE-type and Topological Quivers

We investigate 4D Chern-Simons theory with ADE gauge symmetries in the presence of interacting Wilson and 't Hooft line defects. We analyse the intrinsic properties of these lines' coupling and explicate the building of oscillator-type Lax matrices verifying the RLL integrability equation. We propose gauge quiver diagrams Q$_{G}^{μ}$ encoding the topological data carried by the Lax operators and give several examples where Darboux coordinates are interpreted in terms of topological bi-fundamental matter. We exploit this graphical description $\left( i\right) $ to give new results regarding solutions in representations beyond the fundamentals of $sl_{N}$, $% so_{2N}$ and $e_{6,7}$, and $\left( ii\right) $ to classify the Lax operators for simply laced symmetries in a unified E$_{7}$ CS theory. For quick access, a summary list of the leading topological quivers Q$% _{ADE}^{μ}$ is given in the conclusion section [Figures 29.(a-e), 30.(a-d) and 31.(a-d)].

hep-th↗

arXiv2023

From orthosymplectic structure to super topological matter

Topological supermatter is given by ordinary topological matter constrained by supersymmetry or graded supergroups such as OSP(2N|2N). Using results on super oscillators and lattice QFT$_{d}$, we construct a super tight binding model on hypercubic super lattice with supercharge $ \boldsymbol{Q}=\sum_{\mathbf{k}}\hat{F}_{\mathbf{k}}.\boldsymbol{q}_{\mathbf{k}}.\hat{B}_{\mathbf{k}}$. We first show that the algebraic triplet $(Ω,G,J)$ of super oscillators can be derived from the $OSp(2N|2N)$ supergroup containing the symplectic $Sp(2N)$ and the orthogonal $SO(2N)$ as even subgroups. Then, we apply the obtained result on super oscillating matter to super bands and investigate its topological obstructions protected by TPC symmetries. We also give a classification of the Bose/Fermi coupling matrix $\boldsymbol{q}_{\mathbf{k}}$ in terms of subgroups of $OSp(2N|2N)$\ and show that there are $2P_{N}$ (partition of $N$) classes $\boldsymbol{q}_{\mathbf{k}}$ given by unitary subgroups of $U\left( 2\right) \times U\left( N\right) $. Other features are also given.

hep-th↗

arXiv2022

Lax Operator and superspin chains from 4D CS gauge theory

We study the properties of interacting line defects in the four-dimensional Chern Simons (CS) gauge theory with invariance given by the $SL\left( m|n\right) $ super-group family. From this theory, we derive the oscillator realisation of the Lax operator for superspin chains with $SL(m|n)$ symmetry. To this end, we investigate the holomorphic property of the bosonic Lax operator $\mathcal{L}$ and build a differential equation $% \mathfrak{D}\mathcal{L}=0$ solved by the Costello-Gaioto-Yagi realisation of $\mathcal{L}$ in the framework of\ the CS theory. We generalize this construction to the case of gauge super-groups, and develop a Dynkin super-diagram algorithm to\ deal with the decomposition of the Lie superalgebras. We obtain the generalisation of the Lax operator describing the interaction between the electric Wilson super-lines and the magnetic 't Hooft super-defects. This coupling is given in terms of a mixture of bosonic and fermionic oscillator degrees of freedom in the phase space of magnetically charged 't Hooft super-lines. The purely fermionic realisation of the superspin chain Lax operator is also investigated and it is found to coincide exactly with the $\mathbb{Z}_{2}$- gradation of Lie superalgebras.\ \newline Keywords: 4D Chern-Simons theory, Super-gauge symmetry, Lie superalgebras and Dynkin super-diagrams, Superspin chains and integrability, Super- Lax operator.

hep-th↗

arXiv2022

A signature index for third order topological insulators

In this work, we develop an index signature characterising the third order topological phases in 3D systems. This index is an alternating sum of monomial signatures of Higgs triplet values at 3D corners. We extend our method to N-dimensional systems with open boundaries, and demonstrate that the topological invariant can be efficiently generalised to any space dimension including the second order topological insulators. Known results on lower dimensional systems are recovered and an interpretation in the Higgs space parameters is given.

cond-mat.mes-hall↗

arXiv2021

5D N=1 super QFT: symplectic quivers

We develop a method to build new 5D $\mathcal{N}=1$ gauge models based on Sasaki-Einstein manifolds $Y^{p,q}.$ These models extend the standard 5D ones having a unitary SU$\left( p\right) _{q}$ gauge symmetry based on $% Y^{p,q}$. Particular focus is put on the building of a gauge family with symplectic SP$\left( 2r,\mathbb{R}\right) $ symmetry. These super QFTs are embedded in M-theory compactified on folded toric Calabi-Yau threefolds $% \hat{X}(Y^{2r,0})$ constructed from conical $Y^{2r,0}$. By using outer-automorphism symmetries of 5D $\mathcal{N}=1$\textbf{\ }BPS quivers with unitary SU$\left( 2r\right) $ gauge invariance, we also construct BPS quivers with symplectic SP$\left( 2r,\mathbb{R}\right) $ gauge symmetry. Other related aspects are discussed. Keywords: SCFT$_{5}$, 5D $\mathcal{N}=1$ super QFT on a finite circle, Sasaki-Einstein manifolds, BPS quivers, outer-automorphisms.

hep-th↗

arXiv2011

Anomalous Quantum Hall Effect of 4D Graphene in Background Fields

Boriçi-Creutz (\emph{BC}) model describing the dynamics of light quarks in lattice \emph{QCD} has been shown to be intimately linked to the four dimensional extension of 2D graphene refereed below to as four dimensional graphene (\emph{4D-graphene}). Borrowing ideas from the field theory description of the usual \emph{2D} graphene, we study in this paper the anomalous quantum Hall effect (AQHE) of the \emph{BC} fermions in presence of a constant background field strength $\mathcal{F}_{μν}$ with a special focuss on the case $\mathcal{F}_{μν}=\mathcal{B}ε_{μν34}+\mathcal{E}ε_{12μν}$ with $\mathcal{B}$ and $ \mathcal{E}$ two real\ moduli and $\det \mathcal{F}_{μν}=\mathcal{B}^{2}\mathcal{\times E}^{2}$. First, we revisit the anomalous \emph{2D} graphene by using \emph{QFT} method. Then, we consider the AQHE of \emph{BC}fermions for both regular $\det \mathcal{F}_{μν}\neq 0$ and singular $ \det F_{μν}=0$ cases. We show, amongst others, that the exact solutions of the \emph{BC} fermions coupled to constant $\mathcal{F}_{μν}$ have a 5D interpretation; and the filling factor $ν_{BC}$ of the \emph{BC}\ model coupled to constant $\mathcal{F}_{μν}$ is given by $24% \frac{(2N+1) (2M+1)}{2}$ with $N,$ $M$ positive integers. Others features, such as $\mathcal{F}_{μν}^{QCD}\neq 0$ \textrm{and the extension of the obtained results to the lattice fermions like Karsten-Wilzeck (KW) fermions and naive ones}, are also discussed. Key words: Lattice QCD, Boriçi-Creutz fermions, Anomalous Quantum Hall Effect, filling factor, four dimensional graphene, Index theorem, Spectral flow.

hep-th↗

arXiv2011

Four Dimensional Graphene

Mimicking pristine 2D graphene, we revisit the BBTW model for 4D lattice QCD given in ref.[5] by using the hidden SU(5) symmetry of the 4D hyperdiamond lattice H_4. We first study the link between the H_4 and SU(5); then we refine the BBTW 4D lattice action by using the weight vectors λ_1, λ_2, λ_3, λ_4, λ_5 of the 5-dimensional representation of SU(5) satisfying Σ_iλ_i=0. After that we study explicitly the solutions of the zeros of the Dirac operator D in terms of the SU(5) simple roots α_1, α_2, α_3, α_4 generating H_4; and its fundamental weights ω_1, ω_2, ω_3, ω_4 which generate the reciprocal lattice H_4^\ast. It is shown, amongst others, that these zeros live at the sites of H_4^\ast; and the continuous limit D is given by ((id\surd5)/2) γ^\muk_μwith d, γ^μand k_μstanding respectively for the lattice parameter of H_4, the usual 4 Dirac matrices and the 4D wave vector. Other features such as differences with BBTW model as well as the link between the Dirac operator following from our construction and the one suggested by Creutz using quaternions, are also given. Keywords: Graphene, Lattice QCD, 4D hyperdiamond, BBTW model, SU(5) Symmetry.

hep-th↗

arXiv2011

Monte Carlo simulation of magnetic phase transitions in Mn doped ZnO

The magnetic properties of Mn-doped ZnO semi-conductor have been investigated using the Monte Carlo method within the Ising model. The temperature dependences of the spontaneous magnetization, specific heat and magnetic susceptibility have been constructed for different concentrations of magnetic dopant Mn and different carrier concentrations. The exact values of Mn concentration and carrier concentration at which high temperature transition occurs are determined. An alternative for the explanation of some controversies concerning the existence and the nature of magnetism in Mn diluted in ZnO systems is given. Other features are also studied.

cond-mat.mtrl-sci↗

arXiv2011

Graphene, Lattice QFT and Symmetries

Borrowing ideas from tight binding model, we propose a board class of Lattice QFT models that are classified by the ADE Lie algebras. In the case of su(N) series, we show that the couplings between the quantum states living at the first nearest neighbor sites of the lattice $\mathcal{L}_{su(N)}$ are governed by the complex fundamental representations \underline{${\mathbf{N}}$} and $\bar{\mathbf{N}}$ of $su(N)$; and the second nearest neighbor interactions are described by its adjoint $\underline{\mathbf{N}} \otimes \bar{\mathbf{N}}$. The lattice models associated with the leading su(2), su(3) and su(4) cases are explicitly studied and their fermionic field realizations are given. It is also shown that the su(2) and su(3) models describe respectively the electronic properties of the acetylene chain and the graphene. It is established as well that the energy dispersion of the first nearest neighbor couplings is completely determined by the $A_{N}$ roots $ \mathbfα$ through the typical dependence $N/2+\sum_{roots}\cos(\mathbf{k}.α) $ with $\mathbf{k}$ the wave vector. Other features such as DE extension and other applications are also discussed. Keywords: Tight Binding Model, Graphene, Lattice QFT, ADE Symmetries.

hep-lat↗

arXiv2010

Intersecting Black Attractors in 8D N=1 Supergravity

We study intersecting extremal black attractors in non chiral 8D N=1 supergravity with moduli space ((SO(2,N))/(SO(2)\times SO(N)))\times SO(1,1) and work out explicitly the attractor mechanism for various black p-brane configurations with the typical near horizon geometries AdS_{p+2} \times S^{m} \times T^{6-p-m}. We also give the classification of the solutions of the attractor equations in terms of the SO(N-k) subgroups of SO(2)\times SO(N) symmetry of the moduli space as well as their interpretations in terms of both heterotic string on 2-torus and its type IIA dual. Other features such as non trivial SO(1,7) central charges Z_{μ_1...μ_{p}} in 8D N=1 supergravity and their connections to p-form gauge fields are also given. Key Words: 8D Supergravity, Superstring compactifications, Attractor Mechanism, Intersecting Attractors. PACS numbers: 04.70.-s, 11.25.-w, 04.65.+e, 04.70.-s, 04.50.+h, 04.70.Dy

hep-th↗

arXiv2010

Electronic Properties and Hidden Symmetries of Graphene

Using the relation between the structural and the electronic properties of honeycomb, we study the hidden SU(3) symmetry of the graphene monolayer and exhibit the link with its electronic properties. We show that the conservation law of incoming and outgoing electronic momenta at each site of graphene is solved in terms of SU(3) representations; and the Fourier waves ϕ(k_{x},k_{y}) of the hopping electron may be classified by SU(3) highest weight multiplets ϕ_{p,q}(ξ). It is also shown that the phases arctan((k_{y})/(k_{x})) of the waves are quantized as (((p+q))/((p-q)))sqrt(3) with p, q positive integers. Other features are also discussed.

cond-mat.str-el↗

arXiv2010

Extremal Black Attractors in 8D Maximal Supergravity

Motivated by the new higher D-supergravity solutions on intersecting attractors obtained by Ferrara et al. in [Phys.Rev.D79:065031-2009], we focus in this paper on 8D maximal supergravity with moduli space [SL(3,R)/SO(3)]x[SL(2,R)/SO(2)] and study explicitly the attractor mechanism for various configurations of extremal black p- branes (anti-branes) with the typical near horizon geometries AdS_{p+2}xS^{m}xT^{6-p-m} and p=0,1,2,3,4; 2<=m<=6. Interpretations in terms of wrapped M2 and M5 branes of the 11D M-theory on 3-torus are also given. Keywords: 8D supergravity, black p-branes, attractor mechanism, M-theory.

hep-th↗

arXiv2006

Pure fermionic twistor like model & target space supersymmetry

Using world line fermions $Υ_{\pm}^{m}=Υ_{\pm}^{m}(τ) $ valued in vector representation of $SO(d,4-d) $ with $d=2,3,4,$ we develop a pure fermionic analog of Penrose twistor construction. First, we show that Fermi antisymmetry requiring $(Υ_{\pm}^{m}) ^{2}=0$ can be solved by using twistor like variables. Then we study the corresponding dual twistor like field action and show that quantum spectrum exhibits naturally 4D $\mathcal{N}=1$ target space supersymmetry. Higher spin world line field solutions of the constraint $(Π_{s}^{m}) ^{2}=0$, $s\in \mathbb{Z}$ are also discussed.

hep-th↗

arXiv2004

RG Cascades in Hyperbolic Quiver Gauge Theories

In this paper, we provide a general classification of supersymmeric QFT$_{4}$s into three basic sets: ordinary, affine and indefinite classes. The last class, which has not been enough explored in literature, is shown to share most of properties of ordinary and affine super QFT$_{4}$s. This includes, amongst others, its embedding in type II string on local Calabi-Yau threefolds. We give realizations of these supersymmetric QFT$_{4}$s as D-brane world volume gauge theories. A special interest is devoted to hyperbolic subset for its peculiar features and for the role it plays in type IIB background with non zero axion. We also study RG flows and duality cascades in case of hyperbolic quiver theories. Comments regarding the full indefinite sector are made.

hep-th↗