Publications

Order by: publication date number of citations

• Gravity from thermodynamics: Optimal transport and negative effective dimensions

  Giuseppe Bruno De Luca, Nicolò De Ponti, Andrea Mondino, Alessandro Tomasiello

  SciPost Phys. 15, 039 (2023) · published 1 August 2023 | Toggle abstract · pdf

  We prove an equivalence between the classical equations of motion governing vacuum gravity compactifications (and more general warped-product spacetimes) and a concavity property of entropy under time evolution. This is obtained by linking the theory of optimal transport to the Raychaudhuri equation in the internal space, where the warp factor introduces effective notions of curvature and (negative) internal dimension. When the Reduced Energy Condition is satisfied, concavity can be characterized in terms of the cosmological constant $\Lambda$; as a consequence, the masses of the spin-two Kaluza-Klein fields obey bounds in terms of $\Lambda$ alone. We show that some Cheeger bounds on the KK spectrum hold even without assuming synthetic Ricci lower bounds, in the large class of infinitesimally Hilbertian metric measure spaces, which includes D-brane and O-plane singularities. As an application, we show how some approximate string theory solutions in the literature achieve scale separation, and we construct a new explicit parametrically scale-separated AdS solution of M-theory supported by Casimir energy.

  12 citations

• A model of persistent breaking of continuous symmetry

  Noam Chai, Anatoly Dymarsky, Mikhail Goykhman, Ritam Sinha, Michael Smolkin

  SciPost Phys. 12, 181 (2022) · published 1 June 2022 | Toggle abstract · pdf

  We consider a UV-complete field-theoretic model in general dimensions, including $d=2+1$, that exhibits spontaneous breaking of continuous symmetry, persisting to arbitrarily large temperatures. Our model consists of two copies of the long-range vector models, with $O(m)$ and $O(N-m)$ global symmetry groups, perturbed by double-trace operators. Using conformal perturbation theory we find weakly-coupled IR fixed points for $N\geq 6$ that reveal a spontaneous breaking of global symmetry. Namely, at finite temperature the lower rank group is broken, with the pattern persisting at all temperatures due to scale-invariance. We provide evidence that the models in question are unitary and invariant under full conformal symmetry. Our work generalizes recent results, which considered the particular case of $m=1$ and reported persistent breaking of the discrete $\mathbb{Z}_2=O(1)$. Furthermore, we show that this model exhibits a continuous family of weakly interacting field theories at finite $N$.

  12 citations

• 3d $\mathcal{N}=4$ mirror symmetry with 1-form symmetry

  Satoshi Nawata, Marcus Sperling, Hao Ellery Wang, Zhenghao Zhong

  SciPost Phys. 15, 033 (2023) · published 27 July 2023 | Toggle abstract · pdf

  The study of 3d mirror symmetry has greatly enhanced our understanding of various aspects of 3d $\mathcal{N}=4$ theories. In this paper, starting with known mirror pairs of 3d $\mathcal{N}=4$ quiver gauge theories and gauging discrete subgroups of the flavour or topological symmetry, we construct new mirror pairs with non-trivial 1-form symmetry. By providing explicit quiver descriptions of these theories, we thoroughly specify their symmetries (0-form, 1-form, and 2-group) and the mirror maps between them.

  12 citations

• A roadmap for bootstrapping critical gauge theories: decoupling operators of conformal field theories in $d>2$ dimensions

  Yin-Chen He, Junchen Rong, Ning Su

  SciPost Phys. 11, 111 (2021) · published 22 December 2021 | Toggle abstract · pdf

  We propose a roadmap for bootstrapping conformal field theories (CFTs) described by gauge theories in dimensions $d>2$. In particular, we provide a simple and workable answer to the question of how to detect the gauge group in the bootstrap calculation. Our recipe is based on the notion of \emph{decoupling operator}, which has a simple (gauge) group theoretical origin, and is reminiscent of the null operator of $2d$ Wess-Zumino-Witten CFTs in higher dimensions. Using the decoupling operator we can efficiently detect the rank (i.e. color number) of gauge groups, e.g., by imposing gap conditions in the CFT spectrum. We also discuss the physics of the equation of motion, which has interesting consequences in the CFT spectrum as well. As an application of our recipes, we study a prototypical critical gauge theory, namely the scalar QED which has a $U(1)$ gauge field interacting with critical bosons. We show that the scalar QED can be solved by conformal bootstrap, namely we have obtained its kinks and islands in both $d=3$ and $d=2+\epsilon$ dimensions.

  12 citations

• A spectator-model way to transverse-momentum-dependent gluon distribution functions

  Alessandro Bacchetta, Francesco Giovanni Celiberto, Marco Radici, Pieter Taels

  SciPost Phys. Proc. 8, 040 (2022) · published 12 July 2022 | Toggle abstract · pdf

  We present exploratory analyses of the 3D gluon content of the proton via a study of unpolarized and polarized gluon TMDs at twist-2, calculated in a spectator model for the parent nucleon. Our approach embodies a flexible parametrization for the spectator-mass function, suited to describe both moderate and small-$x$ effects. All these studies can serve as a useful guidance in the investigation of the gluon dynamics inside nucleons and nuclei, which constitutes one of the major goals of new-generation colliding machines, as the EIC, the HL-LHC, NICA, and the FPF.

  12 citations

• CaloDREAM – Detector response emulation via attentive flow matching

  Luigi Favaro, Ayodele Ore, Sofia Palacios Schweitzer, Tilman Plehn

  SciPost Phys. 18, 088 (2025) · published 11 March 2025 | Toggle abstract · pdf

  Detector simulations are an exciting application of modern generative networks. Their sparse high-dimensional data combined with the required precision poses a serious challenge. We show how combining Conditional Flow Matching with transformer elements allows us to simulate the detector phase space reliably. Namely, we use an autoregressive transformer to simulate the energy of each layer, and a vision transformer for the high-dimensional voxel distributions. We show how dimension reduction via latent diffusion allows us to train more efficiently and how diffusion networks can be evaluated faster with bespoke solvers. We showcase our framework, CaloDREAM, on datasets 2 and 3 of the CaloChallenge.

  12 citations

• Analyticity of critical exponents of the $O(N)$ models from nonperturbative renormalization

  Andrzej Chlebicki, Pawel Jakubczyk

  SciPost Phys. 10, 134 (2021) · published 7 June 2021 | Toggle abstract · pdf

  We employ the functional renormalization group framework at the second order in the derivative expansion to study the $O(N)$ models continuously varying the number of field components $N$ and the spatial dimensionality $d$. We in particular address the Cardy-Hamber prediction concerning nonanalytical behavior of the critical exponents $\nu$ and $\eta$ across a line in the $(d,N)$ plane, which passes through the point $(2,2)$. By direct numerical evaluation of $\eta(d,N)$ and $\nu^{-1}(d,N)$ as well as analysis of the functional fixed-point profiles, we find clear indications of this line in the form of a crossover between two regimes in the $(d,N)$ plane, however no evidence of discontinuous or singular first and second derivatives of these functions for $d>2$. The computed derivatives of $\eta(d,N)$ and $\nu^{-1}(d,N)$ become increasingly large for $d\to 2$ and $N\to 2$ and it is only in this limit that $\eta(d,N)$ and $\nu^{-1}(d,N)$ as obtained by us are evidently nonanalytical. By scanning the dependence of the subleading eigenvalue of the RG transformation on $N$ for $d>2$ we find no indication of its vanishing as anticipated by the Cardy-Hamber scenario. For dimensionality $d$ approaching 3 there are no signatures of the Cardy-Hamber line even as a crossover and its existence in the form of a nonanalyticity of the anticipated form is excluded.

  12 citations

• Composing topological domain walls and anyon mobility

  Peter Huston, Fiona Burnell, Corey Jones, David Penneys

  SciPost Phys. 15, 076 (2023) · published 4 September 2023 | Toggle abstract · pdf

  Topological domain walls separating 2+1 dimensional topologically ordered phases can be understood in terms of Witt equivalences between the UMTCs describing anyons in the bulk topological orders. However, this picture does not provide a framework for decomposing stacks of multiple domain walls into superselection sectors — i.e., into fundamental domain wall types that cannot be mixed by any local operators. Such a decomposition can be understood using an alternate framework in the case that the topological order is anomaly-free, in the sense that it can be realized by a commuting projector lattice model. By placing these Witt equivalences in the context of a 3-category of potentially anomalous (2+1)D topological orders, we develop a framework for computing the decomposition of parallel topological domain walls into indecomposable superselection sectors, extending the previous understanding to topological orders with non-trivial anomaly. We characterize the superselection sectors in terms of domain wall particle mobility, which we formalize in terms of tunnelling operators. The mathematical model for the 3-category of topological orders is the 3-category of fusion categories enriched over a fixed unitary modular tensor category.

  12 citations

• A symmetry principle for gauge theories with fractons

  Yuji Hirono, Minyoung You, Stephen Angus, Gil Young Cho

  SciPost Phys. 16, 050 (2024) · published 20 February 2024 | Toggle abstract · pdf

  Fractonic phases are new phases of matter that host excitations with restricted mobility. We show that a certain class of gapless fractonic phases are realized as a result of spontaneous breaking of continuous higher-form symmetries whose conserved charges do not commute with spatial translations. We refer to such symmetries as nonuniform higher-form symmetries. These symmetries fall within the standard definition of higher-form symmetries in quantum field theory, and the corresponding symmetry generators are topological. Worldlines of particles are regarded as the charged objects of 1-form symmetries, and mobility restrictions can be implemented by introducing additional 1-form symmetries whose generators do not commute with spatial translations. These features are realized by effective field theories associated with spontaneously broken nonuniform 1-form symmetries. At low energies, the theories reduce to known higher-rank gauge theories such as scalar/vector charge gauge theories, and the gapless excitations in these theories are interpreted as Nambu-Goldstone modes for higher-form symmetries. Due to the nonuniformity of the symmetry, some of the modes acquire a gap, which is the higher-form analogue of the inverse Higgs mechanism of spacetime symmetries. The gauge theories have emergent nonuniform magnetic symmetries, and some of the magnetic monopoles become fractonic. We identify the 't Hooft anomalies of the nonuniform higher-form symmetries and the corresponding bulk symmetry-protected topological phases. By this method, the mobility restrictions are fully determined by the choice of the commutation relations of charges with translations. This approach allows us to view existing (gapless) fracton models such as the scalar/vector charge gauge theories and their variants from a unified perspective and enables us to engineer theories with desired mobility restrictions.

  12 citations

• Laughable borders: Making the case for the humorous in migration studies

  Anja K. Franck

  Mig. Pol. 1, 004 (2022) · published 14 June 2022 | Toggle abstract · pdf

  Humor is widely recognized as a fundamental aspect of the human experience, that has also played a vital role in the way marginalized groups comment on and mock power. Yet, in migration research the methodological and analytical value of humor has been largely overlooked. Rather, migration studies has commonly centered its analysis around suffering and tragedy and, in the process, depicted migrant trajectories as endeavors largely devoid of laughter, humor, irony and play. This article suggests that such humorless representations of the migration process – and indeed of the migrant subject itself – has broader implications for the types of knowledge that we (re)produce around migrants’ experiences, subjectivities and struggles. In fact, it argues that migration studies’ failure to recognize migrants as humorous individuals risks feeding into processes of exceptionalization and de-humanization through setting “the migrant” up as an obscure figure that lacks “essentially human” qualities. In order to make the case for the humorous in migration research, the article illustrates how refugees arriving to the Greek island of Lesvos in the early summer of 2015 laughed at their own predicament as well as the technologies put in place to control their freedom of movement and how their laughter, humor and comic displays did important political work in refusing subjugation, in speaking truth to power and in capturing the absurdity of the violence that they faced.

  12 citations