arXiv subjects

Matteo Lotito

Publications and source records attributed to Matteo Lotito.

15 recordsLinked to original sources

arXiv2026

Strongly-coupled black holes (are not) at weak coupling

We prove sharp bounds on the moduli space excursion that is possible outside the event horizon of a spherically symmetric charged black hole. In regions where the black hole charge $Q (\phi)$ is no less than its asymptotic value, we prove that the total moduli space excursion is less than $\frac{\pi}{2\sqrt{k_N}}$ where $k_N$ is the rationalized Newton constant. We also show that the moduli space excursion in a specified direction in which $Q (\phi)$ is non-decreasing satisfies the same bound. Applying our bound to electrically charged black holes, we rule out a potential loophole in a recent proof [arXiv:2401.14449] of the Weak Gravity Conjecture in perturbative bosonic string theory.

hep-th↗

arXiv2026

The weak gravity conjecture in perturbative strings

In this note we give a summary of [arXiv:2401.14449] in which we proposed a proof of the weak gravity conjecture in perturbative string theory. While the WGC is well established, checked in many examples, and many of the ingredients we use have previously appeared in the literature, a comprehensive proof from the top-down was still missing. The present work focuses on the bosonic string as a proof of concept, while the generalization to superstring cases is to appear in a forthcoming paper. This note is based heavily on [arXiv:2401.14449] and on a talk given at the Corfu2025 Workshop on Quantum Gravity and Strings.

hep-th↗

arXiv2026

UV/IR relations from the worldsheet

We derive universal scaling relations for the low-energy effective action of string theory, connecting the vacuum energy and gauge couplings to higher-derivative Wilson coefficients. At one-loop in string perturbation theory, these generic parametric relations follow from modular and conformal invariance of the worldsheet, independently of the specific low-energy phase of the theory, and they become non-trivial in species limits. As a result, we substantially strengthen our previous case for the emergent string conjecture and connect UV/IR mixing to swampland principles. We argue that our results persist to higher loops, hinting at a pathway to study strong couplings using dualities. Further accounting for open-string contributions, if any, our results lead to parametric inequalities which reproduce holographic bounds and support the magnetic weak-gravity conjecture and the dark dimension scenario.

hep-th↗

arXiv2025

Special K\"ahler geometries of $\mathcal{N}=4$ superYang-Mills

The low energy effective theory on the moduli space of vacua of 4d superYang-Mills (sYM) theory defines a special K\"ahler geometry. For simple sYM gauge algebras, $\mathfrak{g}$, we classify all compatible special K\"ahler structures by showing that they are in one-to-one correspondence with certain equivalence classes of integral symplectic representations of the Weyl group of $\mathfrak{g}$. We further demonstrate that, for principal Dirac pairing, these equivalence classes are in one-to-one correspondence with the S-duality orbits of the global structures of the corresponding $\mathfrak{g}$ sYM gauge theory, after a mistake in the field theory literature is corrected. This provides a low-energy test of S-duality. We also discuss twisted product geometries made from factors with special K\"ahler structures with non-principal Dirac pairings.

hep-th↗

arXiv2024

Twists of superconformal algebras

We take first steps toward a theory of ``conformal twists'' for superconformal field theories in dimension 3 to 6, extending the well-known analysis of twists for supersymmetric theories. A conformal twist is a square-zero odd element in the superconformal Lie algebra, and we classify all twists and describe their orbits under the adjoint action of the superconformal group. We work mostly with the complexified superconformal algebras, unless explicitly stated otherwise; real forms of the superconformal algebra may have important physical implications, but we only discuss these subtleties in a few special cases. Conformal twists can give rise to interesting subalgebras and protected sectors of operators in a superconformal field theory, with the Donaldson--Witten topological field theory and the vertex operator algebras of 4-dimensional N=2 SCFTs being prominent examples. To obtain mathematical precision, we explain how to extract vertex algebras and E_n algebras from a twisted superconformal field theory using factorization algebras.

math-ph↗

arXiv2024

Proving the Weak Gravity Conjecture in Perturbative String Theory, Part I: The Bosonic String

We present a complete proof of the Weak Gravity Conjecture in any perturbative bosonic string theory in spacetime dimension $D\ge6$. Our proof works by relating the black hole extremality bound to long range forces, which are more easily calculated on the worldsheet, closing the gaps in partial arguments in the existing literature. We simultaneously establish a strict, sublattice form of the conjecture in the same class of theories. We close by discussing the scope and limitations of our analysis, along with possible extensions including an upcoming generalization of our work to the superstring.

hep-th↗

arXiv2022

Vertex algebra of extended operators in 4d N=2 superconformal field theories

We construct a class of extended operators in the cohomology of a pair of twisted Schur supercharges of 4d N=2 SCFTs. The extended operators are constructed from the local operators in this cohomology -- the Schur operators -- by a version of topological descent. They are line, surface, and domain wall world volume integrals of certain super descendants of Schur operators. Their world volumes extend in directions transverse to a spatial plane in Minkowski space-time. As operators in the cohomology of these twisted Schur supercharges, their correlators are (locally) meromorphic functions only of the positions where they intersect this plane. This implies the extended operators enlarge the vertex operator algebra of the Schur operators. We illustrate this enlarged vertex algebra by computing some extended-operator product expansions within a subalgebra of it for the free hypermultiplet SCFT.

hep-th↗

arXiv2021

Deconfining $\mathcal{N}=2$ SCFTs, or the Art of Brane Bending

We introduce a systematic approach to constructing $\mathcal{N}=1$ Lagrangians for a class of interacting $\mathcal{N}=2$ SCFTs. We analyse in detail the simplest case of the construction, arising from placing branes at an orientifolded $\mathbb{C}^2/\mathbb{Z}_2$ singularity. In this way we obtain Lagrangian descriptions for all the $R_{2,k}$ theories. The rank one theories in this class are the $E_6$ Minahan-Nemeschansky theory and the $C_2\times U(1)$ Argyres-Wittig theory. The Lagrangians that arise from our brane construction manifestly exhibit either the entire expected flavour symmetry group of the SCFT (for even $k$) or a full-rank subgroup thereof (for odd $k$), so we can compute the full superconformal index of the $\mathcal{N}=2$ SCFTs, and also systematically identify the Higgsings associated to partial closing of punctures.

hep-th↗

arXiv2018

Flavor symmetries and the topology of special K\"ahler structures at rank 1

We propose a method for determining the flavor charge lattice of the continuous flavor symmetry of rank-1 4d N = 2 superconformal field theories (SCFTs) and IR free gauge theories from topological invariants of the special K\"ahler structure of the mass-deformed Coulomb branches (CBs) of the theories. The method is based on the middle homology of the total space of the elliptic fibration over the CB, and is a generalization of the F-theory string web description of flavor charge lattices. The resulting lattices, which we call 'string web lattices', contain not only information about the flavor symmetry of the SCFT but also additional information encoded in the lattice metric derived from the middle homology intersection form. This additional information clearly reflects the low energy electric and magnetic charges of BPS states on the CB, but there are other properties of the string web lattice metric which we have not been able to understand in terms of properties of the BPS spectrum. We compute the string web lattices of all rank-1 SCFTs and IR free gauge theories. We find agreement with results obtained by other methods, and find in a few cases that the string web lattice gives additional information on the flavor symmetry.

hep-th↗

arXiv2016

Collider Signatures of Flavorful Higgs Bosons

Motivated by our limited knowledge of the Higgs couplings to first two generation fermions, we analyze the collider phenomenology of a class of two Higgs doublet models (2HDMs) with a non-standard Yukawa sector. One Higgs doublet is mainly responsible for the masses of the weak gauge bosons and the third generation fermions, while the second Higgs doublet provides mass for the lighter fermion generations. The characteristic collider signatures of this setup differ significantly from well-studied 2HDMs with natural flavor conservation, flavor alignment, or minimal flavor violation. New production mechanisms for the heavy scalar, pseudoscalar, and charged Higgs involving second generation quarks can become dominant. The most interesting decay modes include H/A -> cc, tc, {\mu}{\mu}, {\tau}{\mu} and H+ -> cb, cs, {\mu}{\nu}. Searches for low mass di-muon resonances are currently among the best probes of the heavy Higgs bosons in this setup.

hep-ph↗

arXiv2016

Geometric constraints on the space of N=2 SCFTs III: enhanced Coulomb branches and central charges

This is the third in a series of three papers on the systematic analysis of rank 1 four dimensional $\mathcal{N}=2$ SCFTs. In the first two papers we developed and carried out a strategy for classifying and constructing physical planar rank-1 Coulomb branch geometries of $\mathcal{N}=2$ SCFTs. Here we describe general features of the Higgs and mixed branch geometries of the moduli space of these SCFTs, and use this, along with their Coulomb branch geometry, to compute their conformal and flavor central charges. We conclude with a summary of the state of the art for rank-1 $\mathcal{N}=2$ SCFTs.

hep-th↗

arXiv2016

Expanding the landscape of $\mathcal{N}$=2 rank 1 SCFTs

We refine our previous proposal for systematically classifying 4d rank-1 $\mathcal N=2$ SCFTs by constructing their possible Coulomb branch geometries. Four new recently discussed rank-1 theories, including novel $\mathcal{N}=3$ SCFTs, sit beautifully in our refined classification framework. By arguing for the consistency of their RG flows we can make a strong case for the existence of at least four additional rank-1 SCFTs, nearly doubling the number of known rank-1 SCFTs. The refinement consists of relaxing the assumption that the flavor symmetries of the SCFTs have no discrete factors. This results in an enlarged (but finite) set of possible rank-1 SCFTs. Their existence can be further constrained using consistency of their central charges and RG flows.

hep-th↗

arXiv2015

Geometric constraints on the space of N=2 SCFTs II: Construction of special K\"ahler geometries and RG flows

This is the second in a series of three papers on systematic analysis of rank 1 Coulomb branch geometries of four dimensional $\mathcal{N}$=2 SCFTs. In the first paper we developed a strategy for classifying physical rank-1 CB geometries of $\mathcal{N}$=2 SCFTs. Here we show how to carry out this strategy computationally to construct the Seiberg-Witten curves and one-forms for all the rank-1 SCFTs. Explicit expressions are given for all cases, with the exception of the $N_f$=4 SU(2) gauge theory and the En SCFTs which were previously constructed. Our classification includes all known rank-1 theories plus a new one with an abelian flavor group, plus nine additional theories whose existence is more speculative. Four of those, reported in our first paper, depend on the assumption of new frozen rank-1 SCFTs. Here we also also show that the assumption of the existence of certain rank-0 $\mathcal{N}$=2 SCFTs leads to five additional consistent rank-1 CB geometries.

hep-th↗

arXiv2015

Geometric constraints on the space of N=2 SCFTs I: physical constraints on relevant deformations

We initiate a systematic study of four dimensional $\mathcal{N}=2$ superconformal field theories (SCFTs) based on the analysis of their Coulomb branch geometries. Because these SCFTs are not uniquely characterized by their scale-invariant Coulomb branch geometries we also need information on their deformations. We construct all inequivalent such deformations preserving $\mathcal{N}=2$ supersymmetry and additional physical consistency conditions in the rank 1 case. These not only include all the ones previously predicted by S-duality, but also 16 additional deformations satisfying all the known $\mathcal{N}=2$ low energy consistency conditions. All but two of these additonal deformations have recently been identified with new rank 1 SCFTs; these identifications are briefly reviewed. Some novel ingredients which are important for this study include: a discussion of RG-flows in the presence of a moduli space of vacua; a classification of local $\mathcal{N}=2$ supersymmetry-preserving deformations of unitary $\mathcal{N}=2$ SCFTs; and an analysis of charge normalizations and the Dirac quantization condition on Coulomb branches. This paper is the first in a series of three. The second paper, 1601.00011, gives the details of the explicit construction of the Coulomb branch geometries discussed here, while the third, 1609.04404, discusses the computation of central charges of the associated SCFTs.

hep-th↗

arXiv2014

Group Momentum Space and Hopf Algebra Symmetries of Point Particles Coupled to 2+1 Gravity

We present an in-depth investigation of the ${\rm SL}(2,\mathbb{R})$ momentum space describing point particles coupled to Einstein gravity in three space-time dimensions. We introduce different sets of coordinates on the group manifold and discuss their properties under Lorentz transformations. In particular we show how a certain set of coordinates exhibits an upper bound on the energy under deformed Lorentz boosts which saturate at the Planck energy. We discuss how this deformed symmetry framework is generally described by a quantum deformation of the Poincar\'e group: the quantum double of ${\rm SL}(2,\mathbb{R})$. We then illustrate how the space of functions on the group manifold momentum space has a dual representation on a non-commutative space of coordinates via a (quantum) group Fourier transform. In this context we explore the connection between Weyl maps and different notions of (quantum) group Fourier transform appeared in the literature in the past years and establish relations between them.

gr-qc↗