Publications

2022

Report of the Topical Group on Top quark physics and heavy flavor production for Snowmass 2021
- Schwienhorst Reinhard
- Wackeroth Doreen
- Agashe Kaustubh
- Alioli Simone
- Aparisi Javier
- Bevilacqua Giuseppe
- Bi Huan-Yu
- Brock Raymond
- Camacho Abel Gutierrez
- Cordero Fernando Febres
- de Blas Jorge
- Demina Regina
- Du Yong
- Durieux Gauthier
- Fein Jarrett
- Franceschini Roberto
- Fuster Juan
- Garzelli Maria Vittoria
- Gavardi Alessandro
- Gombas Jason
- Grojean Christoph
- Gu Jiale
- Guzzi Marco
- Hartanto Heribertus Bayu
- Hoang Andre
- Holguin Jack
- Irles Adrian
- Kidonakis Nikolaos
- Kim Dojin
- Kraus Manfred
- Lepenik Christopher
- Liss Tony M.
- Mantani Luca
- Mantry Sonny
- Mateu Vicent
- Melini Davide
- Michel J.
- Miralles Victor
- Lopez Marcos Miralles
- Llacer Maria Moreno
- Moch Sven-Olaf
- Nadolsky Pavel
- Neumann Tobias
- Narain Meenakshi
- Nasufi Jasmina
- Nowak Kacper
- Pathak Aditya
- Peskin Michael
- Poncelet Rene
- Procura Massimiliano
- Reina Laura
- Rodrigo G.
- Sathyan Deepak
- Sawford Sara
- Simon Frank
- Spira Michael
- Stewart Ian
- Tairafune Seidai
- Tian Junping
- Tricoli Alessandro
- Uwer Peter
- Vryonidou Eleni
- Voss Katharina
- Vos Marcel
- Worek Malgorzata
- Xie Keping
- Yamamoto Hitoshi
- Yunamine Ryo
- Yu Zhite
- Yuan C. -P.
- Zarnecki Aleksander Filip
, 2022. This report summarizes the work of the Energy Frontier Topical Group on EW Physics: Heavy flavor and top quark physics (EF03) of the 2021 Community Summer Study (Snowmass). It aims to highlight the physics potential of top-quark studies and heavy-flavor production processes (bottom and charm) at the HL-LHC and possible future hadron and lepton colliders and running scenarios.
Probabilistic picture for particle number densities in stretched tips of the branching Brownian motion
- Le Anh Dung
- Mueller Alfred H.
- Munier Stéphane
EPL - Europhysics Letters, European Physical Society / EDP Sciences / Società Italiana di Fisica / IOP Publishing, 2022, 140 (5), pp.51003. In the framework of a stochastic picture for the one-dimensional branching Brownian motion, we compute the probability density of the number of particles near the rightmost one at a time $T$, that we take very large, when this extreme particle is conditioned to arrive at a predefined position $x_T$ chosen far ahead of its expected position $m_T$. We recover the previously-conjectured fact that the typical number density of particles a distance $\Delta$ to the left of the lead particle, when both $\Delta$ and $x_T-\Delta-m_T$ are large, is smaller than the mean number density by a factor proportional to $e^{-\zeta\Delta^{2/3}}$, where $\zeta$ is a constant that was so far undetermined. Our picture leads to an expression for the probability density of the particle number, from which a value for $\zeta$ may be inferred. (10.1209/0295-5075/aca699)
DOI : 10.1209/0295-5075/aca699
Black holes in dS$_3$
- Emparan Roberto
- Pedraza Juan F.
- Svesko Andrew
- Tomašević Marija
- Visser Manus R.
Journal of High Energy Physics, Springer, 2022, 11, pp.073. In three-dimensional de Sitter space classical black holes do not exist, and the Schwarzschild-de Sitter solution instead describes a conical defect with a single cosmological horizon. We argue that the quantum backreaction of conformal fields can generate a black hole horizon, leading to a three-dimensional quantum de Sitter black hole. Its size can be as large as the cosmological horizon in a Nariai-type limit. We show explicitly how these solutions arise using braneworld holography, but also compare to a non-holographic, perturbative analysis of backreaction due to conformally coupled scalar fields in conical de Sitter space. We analyze the thermodynamics of this quantum black hole, revealing it behaves similarly to its classical four-dimensional counterpart, where the generalized entropy replaces the classical Bekenstein-Hawking entropy. We compute entropy deficits due to nucleating the three-dimensional black hole and revisit arguments for a possible matrix model description of dS spacetimes. Finally, we comment on the holographic dual description for dS spacetimes as seen from the braneworld perspective. (10.1007/JHEP11(2022)073)
DOI : 10.1007/JHEP11(2022)073
Jet Broadening in Flowing Matter -- Resummation
- Andres Carlota
- Dominguez Fabio
- Sadofyev Andrey V.
- Salgado Carlos A.
Physical Review D, American Physical Society, 2022, 106 (7), pp.074023. In this work, we obtain the leading corrections to the jet momentum broadening distribution in a QCD medium arising from the transverse flow of the matter. We first derive the single-particle propagator of a highly energetic parton resumming its multiple interactions with the homogeneous flowing matter, explicitly keeping the leading subeikonal flow terms. Then, we use this propagator to obtain the jet broadening distribution and its leading moments. We show that this distribution becomes anisotropic in the presence of transverse flow, since its odd moments are generally non-zero and proportional to the transverse velocity of the medium. Finally, we evaluate several odd moments, which we compare to the corresponding results at first order in opacity, showing that accounting for multiple in-medium scatterings is essential to describe some observables in dense nuclear matter. (10.1103/PhysRevD.106.074023)
DOI : 10.1103/PhysRevD.106.074023
Holography from Singular Supertranslations on a Black Hole Horizon
- Akhoury Ratindranath
- Choi Sangmin
- Perry Malcolm J.
Physical Review Letters, American Physical Society, 2022, 129 (22), pp.221603. We investigate the standard and dual BMS supertranslation generators on a black hole horizon and draw some conclusions about black hole physics. Recently, it has been shown that in addition to conventional BMS supertranslation symmetries, there exists an additional infinite set of magnetic asymptotic symmetries, dual BMS supertranslations, again parametrized by a function on the two-sphere. We show that the Dirac bracket between these generators exhibits an anomalous central term when one parameter function exhibits a singularity in the complex stereographical coordinates on the sphere. In order to preserve general coordinate invariance, we demonstrate that this central term can be removed by postulating a holographic gravitational Chern-Simons theory on the horizon. This indicates that for an anomaly-free theory of quantum gravity in the presence of a black hole, one should include a boundary theory on the horizon. (10.1103/PhysRevLett.129.221603)
DOI : 10.1103/PhysRevLett.129.221603
Destroying superconductivity in thin films with an electric field
- Amoretti Andrea
- Brattan Daniel K.
- Magnoli Nicodemo
- Martinoia Luca
- Matthaiakakis Ioannis
- Solinas Paolo
Phys.Rev.Res., 2022, 4 (3), pp.033211. In this paper, we use a Ginzburg-Landau approach to show that a suitably strong electric field can drive a phase transition from a superconductor to a normal metal. The transition is induced by taking into account corrections to the permittivity due to the superconductive gap and persists even when screening effects are considered. We test the model against recent experimental observations in which a strong electric field has been observed to control the supercurrent in superconducting thin films. We find excellent agreement with the experimental data and are able to explain several observed features. We additionally suggest a way to test our theoretical proposal via superconductor-superconductor electron tunneling. (10.1103/PhysRevResearch.4.033211)
DOI : 10.1103/PhysRevResearch.4.033211
Revisiting the Carrollian scalar field
- Rivera-Betancour David
- Vilatte Matthieu
Physical Review D, American Physical Society, 2022, 106 (8), pp.085004. We investigate the (conformally coupled) scalar field on a general Carrollian spacetime in arbitrary dimension. The analysis discloses electric and magnetic dynamics. For both, we provide the energy and the momenta of the field, accompanied by their conservation equations. We discuss the conservation and nonconservation properties resulting from the existence of conformal isometries and the associated charges. We illustrate those results for a scalar field propagating on the null boundary of four-dimensional Ricci-flat Robinson-Trautman spacetimes. (10.1103/PhysRevD.106.085004)
DOI : 10.1103/PhysRevD.106.085004
Goldilocks modes and the three scattering bases
- Donnay Laura
- Pasterski Sabrina
- Puhm Andrea
Journal of High Energy Physics, Springer, 2022, 06, pp.124. We consider massless scattering from the point of view of the position, momentum, and celestial bases. In these three languages different properties of physical processes become manifest or obscured. Within the soft sector, they highlight distinct aspects of the infrared triangle: quantum field theory soft theorems arise in the limit of vanishing energy ω, memory effects are described via shifts of fields at the boundary along the null time coordinate u, and celestial symmetry algebras are realized via currents that appear at special values of the conformal dimension ∆. We focus on the subleading soft theorems at ∆ = 1 − s for gauge theory (s = 1) and gravity (s = 2) and explore how to translate the infrared triangle to the celestial basis. We resolve an existing tension between proposed overleading gauge transformations as examined in the position basis and the ‘Goldstone-like’ modes where we expect celestial symmetry generators to appear. In the process we elucidate various order-of-limits issues implicit in the celestial formalism. We then generalize our construction to the tower of w$_{1+∞}$ generators in celestial CFT, which probe further subleading-in-ω soft behavior and are related to subleading-in-r vacuum transitions that measure higher multipole moments of scatterers. In the end we see that the celestial basis is ‘just right’ for identifying the symmetry structure. (10.1007/JHEP06(2022)124)
DOI : 10.1007/JHEP06(2022)124
Sachdev-Ye-Kitaev Models and Beyond: A Window into Non-Fermi Liquids
- Chowdhury Debanjan
- Georges Antoine
- Parcollet Olivier
- Sachdev Subir
Reviews of Modern Physics, American Physical Society, 2022, 94 (3), pp.035004. We present a review of the Sachdev-Ye-Kitaev (SYK) model of compressible quantum many-body systems without quasiparticle excitations, and its connections to various theoretical studies of non-Fermi liquids in condensed matter physics. The review is placed in the context of numerous experimental observations on correlated electron materials. Strong correlations in metals are often associated with their proximity to a Mott transition to an insulator created by the local Coulomb repulsion between the electrons. We explore the phase diagrams of a number of models of such local electronic correlation, employing a dynamical mean field theory in the presence of random spin exchange interactions. Numerical analyses and analytical solutions, using renormalization group methods and expansions in large spin degeneracy, lead to critical regions which display SYK physics. The models studied include the single-band Hubbard model, the $t$-$J$ model and the two-band Kondo-Heisenberg model in the presence of random spin exchange interactions. We also examine non-Fermi liquids obtained by considering each SYK model with random four-fermion interactions to be a multi-orbital atom, with the SYK-atoms arranged in an infinite lattice. We connect to theories of sharp Fermi surfaces without any low-energy quasiparticles in the absence of spatial disorder, obtained by coupling a Fermi liquid to a gapless boson; a systematic large $N$ theory of such a critical Fermi surface, with SYK characteristics, is obtained by averaging over an ensemble of theories with random boson-fermion couplings. Finally, we present an overview of the links between the SYK model and quantum gravity and end with an outlook on open questions. (10.1103/RevModPhys.94.035004)
DOI : 10.1103/RevModPhys.94.035004
Holographic complexity of quantum black holes
- Emparan Roberto
- Frassino Antonia Micol
- Sasieta Martin
- Tomašević Marija
Journal of High Energy Physics, Springer, 2022, 02, pp.204. We analyze different holographic complexity proposals for black holes that include corrections from bulk quantum fields. The specific setup is the quantum BTZ black hole, which encompasses in an exact manner the effects of conformal fields with large central charge in the presence of the black hole, including the backreaction corrections to the BTZ metric. Our results show that Volume Complexity admits a consistent quantum expansion and correctly reproduces known limits. On the other hand, the generalized Action Complexity picks up large contributions from the singularity, which is modified due to quantum backreaction, with the result that Action Complexity does not reproduce the expected classical limit. Furthermore, we show that the doubly-holographic setup allows computing the complexity coming purely from quantum fields — a notion that has proven evasive in usual holographic setups. We find that in holographic induced-gravity scenarios the complexity of quantum fields in a black hole background vanishes to leading order in the gravitational strength of CFT effects. (10.1007/JHEP02(2022)204)
DOI : 10.1007/JHEP02(2022)204
Regge trajectories for the (2, 0) theories
- Lemos Madalena
- van Rees Balt C.
- Zhao Xiang
Journal of High Energy Physics, Springer, 2022, 2022 (01), pp.022. We investigate the structure of conformal Regge trajectories for the maximally supersymmetric (2, 0) theories in six dimensions. The different conformal multiplets in a single superconformal multiplet must all have similarly-shaped Regge trajectories. We show that these super-descendant trajectories interact in interesting ways, leading to new constraints on their shape. For the four-point function of the stress tensor multiplet supersymmetry also softens the Regge behavior in some channels, and consequently we observe that ‘analyticity in spin’ holds for all spins greater than −3. All the physical operators in this correlator therefore lie on Regge trajectories and we describe an iterative scheme where the Lorentzian inversion formula can be used to bootstrap the four-point function. Some numerical experiments yield promising results, with OPE data approaching the numerical bootstrap results for all theories with rank greater than one. (10.1007/JHEP01(2022)022)
DOI : 10.1007/JHEP01(2022)022
Bounds on gravitational brane couplings and tomography in AdS$_{3}$ black hole microstates
- Lee Ji Hoon
- Neuenfeld Dominik
- Shukla Ashish
Journal of High Energy Physics, Springer, 2022, 10, pp.139. We study information theoretic properties of planar black hole microstates in 2 + 1 dimensional asymptotically anti-de Sitter spacetime, modeled by black holes with an end-of-the-world brane behind the horizon. The von Neumann entropy of sufficiently large subregions in the dual CFT exhibits a time-dependent phase, which from a doubly-holographic perspective corresponds to the appearance of quantum extremal islands in the brane description. Considering the case where dilaton gravity is added to the brane, we show that tuning the associated couplings affects the propagation of information in the dual CFT state. By requiring that information theoretic bounds on the growth of entanglement entropy are satisfied in the dual CFT, we can place bounds on the allowed values of the couplings on the brane. Furthermore, we initiate the study of brane tomography, by showing how subleading corrections to the entanglement velocity can be used to learn about the properties of the brane as well as any gravitational dynamics localized on it. (10.1007/JHEP10(2022)139)
DOI : 10.1007/JHEP10(2022)139
Entanglement spectrum and quantum phase diagram of the long-range XXZ chain
- Schneider J.T.
- Thomson S.J.
- Sanchez-Palencia L.
Physical Review B, American Physical Society, 2022, 106 (1), pp.014306. Entanglement is a central feature of many-body quantum systems and plays a unique role in quantum phase transitions. In many cases, the entanglement spectrum, which represents the spectrum of the density matrix of a bipartite system, contains valuable information beyond the sole entanglement entropy. Here we investigate the entanglement spectrum of the long-range XXZ model. We show that within the critical phase it exhibits a remarkable self-similarity. The breakdown of self-similarity and the transition away from a Luttinger liquid is consistent with renormalization group theory. Combining the two, we are able to determine the quantum phase diagram of the model and locate the corresponding phase transitions. Our results are confirmed by numerically-exact calculations using tensor-network techniques. Moreover, we show that the self-similar rescaling extends to the geometrical entanglement as well as the Luttinger parameter in the critical phase. Our results pave the way to further studies of entanglement properties in long-range quantum models. (10.1103/PhysRevB.106.014306)
DOI : 10.1103/PhysRevB.106.014306
Spectral and intensity control of high energy terahertz radiation from bulk liquids
- Rakesh Kumar V.
- Jana Kamalesh
- Dey Indranuj
- Chandra Vardhan K.
- Lad Amit D.
- Brown Jeffrey M.
- Gaarde Mette B.
- Couairon Arnaud
- Ravindra Kumar G.
Journal of Physics D: Applied Physics, IOP Publishing, 2022, 55. High power, broadband terahertz (THz) radiation from liquids, excited by intense, femtosecond 800 nm laser pulses has been demonstrated recently, overturning the long held belief that liquids would not give such emission due to their absorption in the THz region. Given the widespread interest in the use of THz radiation for several applications and the energy and bandwidth limitations of existing sources, liquids are expected to attract great attention in the future. While the emission at tens of microjoules from liquids is very promising, it is important to explore whether control of the THz flux and spectrum is achievable by manipulating the laser or liquid parameters. In this paper we present results on manipulating the spectrum of THz radiation from liquids by chirping the input laser pulse and optimizing the THz output energy by laser chirp as well as optimizing the focal position. We demonstrate tunability by varying the chirp of the laser pulse and show that the THz emission predominantly comes from the region near the end of the liquid path, consistent with the absorption of THz radiation by liquids. This control gives us an opportunity to tune the THz radiation to suit experimental needs. We present simulations that support the results. (10.1088/1361-6463/ac3455)
DOI : 10.1088/1361-6463/ac3455
Physique de la matière condensée
- Georges Antoine
L'Annuaire du Collège de France. Résumés des cours et travaux, Collège de France, 2022 (119), pp.95-98. (10.4000/annuaire-cdf.16837)
DOI : 10.4000/annuaire-cdf.16837
Black tsunamis and naked singularities in AdS
- Emparan Roberto
- Licht David
- Suzuki Ryotaku
- Tomašević Marija
- Way Benson
Journal of High Energy Physics, Springer, 2022, 02, pp.090. We study the evolution of the Gregory-Laflamme instability for black strings in global AdS spacetime, and investigate the CFT dual of the formation of a bulk naked singularity. Using an effective theory in the large D limit, we uncover a rich variety of dynamical behaviour, depending on the thickness of the string and on initial perturbations. These include: large inflows of horizon generators from the asymptotic boundary (a ‘black tsunami’); a pinch-off of the horizon that likely reveals a naked singularity; and competition between these two behaviours, such as a nakedly singular pinch-off that subsequently gets covered by a black tsunami. The holographic dual describes different patterns of heat flow due to the Hawking radiation of two black holes placed at the antipodes of a spherical universe. We also present a model that describes, in any D, the burst in the holographic stress-energy tensor when the signal from a bulk self-similar naked singularity reaches the boundary. The model shows that the shear components of the boundary stress diverge in finite time, while the energy density and pressures from the burst vanish. (10.1007/JHEP02(2022)090)
DOI : 10.1007/JHEP02(2022)090
Prospects for quarkonium studies at the high-luminosity LHC
- Chapon Emilien
- d'Enterria David
- Ducloue Bertrand
- Echevarria Miguel G.
- Gossiaux Pol-Bernard
- Kartvelishvili Vato
- Kasemets Tomas
- Lansberg Jean-Philippe
- Mcnulty Ronan
- Price Darren D.
- Shao Hua-Sheng
- van Hulse Charlotte
- Winn Michael
- Adam Jaroslav
- An Liupan
- Villar Denys Yen Arrebato
- Bhattacharya Shohini
- Celiberto Francesco G.
- Cheshkov Cvetan
- d'Alesio Umberto
- da Silva Cesar
- Ferreiro Elena G.
- Flett Chris A.
- Flore Carlo
- Garzelli Maria Vittoria
- Gaunt Jonathan
- He Jibo
- Makris Yiannis
- Marquet Cyrille
- Massacrier Laure
- Mehen Thomas
- Mezrag Cedric
- Micheletti Luca
- Nagar Riccardo
- Nefedov Maxim A.
- Ozcelik Melih A.
- Paul Biswarup
- Pisano Cristian
- Qiu Jian-Wei
- Rajesh Sangem
- Rinaldi Matteo
- Scarpa Florent
- Smith Maddie
- Taels Pieter
- Tee Amy
- Teryaev Oleg
- Vitev Ivan
- Watanabe Kazuhiro
- Yamanaka Nodoka
- Yao Xiaojun
- Zhang Yanxi
Prog.Part.Nucl.Phys., 2022, 122, pp.103906. Prospects for quarkonium-production studies accessible during the upcoming high-luminosity phases of the CERN Large Hadron Collider operation after 2021 are reviewed. Current experimental and theoretical open issues in the field are assessed together with the potential for future studies in quarkonium-related physics. This will be possible through the exploitation of the huge data samples to be collected in proton–proton, proton–nucleus and nucleus–nucleus collisions, both in the collider and fixed-target modes. Such investigations include, among others, those of: (i) <math display="inline" id="d1e8603" altimg="si149.svg"><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math> and <math display="inline" id="d1e8613" altimg="si276.svg"><mi>Υ</mi></math> produced in association with other hard particles; (ii) <math display="inline" id="d1e8618" altimg="si3.svg"><msub><mrow><mi>χ</mi></mrow><mrow><mi>c</mi><mo>,</mo><mi>b</mi></mrow></msub></math> and <math display="inline" id="d1e8633" altimg="si4.svg"><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi><mo>,</mo><mi>b</mi></mrow></msub></math> down to small transverse momenta; (iii) the constraints brought in by quarkonia on gluon PDFs, nuclear PDFs, TMDs, GPDs and GTMDs, as well as on the low-<math display="inline" id="d1e8647" altimg="si5.svg"><mi>x</mi></math> parton dynamics; (iv) the gluon Sivers effect in polarised-nucleon collisions; (v) the properties of the quark–gluon plasma produced in ultra-relativistic heavy-ion collisions and of collective partonic effects in general; and (vi) double and triple parton scatterings. (10.1016/j.ppnp.2021.103906)
DOI : 10.1016/j.ppnp.2021.103906
Deuteron relativistic charge distributions
- Lorcé Cédric
- Wang Pierre
Physical Review D, American Physical Society, 2022, 105 (9), pp.096032. We study the relativistic 2D charge distributions in the case of a spin-1 target. These charge distributions are based on a phase-space approach allowing one to study their frame dependence, and hence to relate the familiar rest-frame picture with the light-front picture developed in the last two decades. Like in the spin-<math display="inline"><mn>1</mn><mo>/</mo><mn>2</mn></math> case, we show that relativistic kinematical effects associated with spin are responsible for the distortions of the charge distributions seen in a moving frame. Applying our results to the deuteron, we observe a mild frame dependence compared to the nucleon case. (10.1103/PhysRevD.105.096032)
DOI : 10.1103/PhysRevD.105.096032
Massless Scalars and Higher-Spin BMS in Any Dimension
- Bekaert Xavier
- Oblak Blagoje
Journal of High Energy Physics, Springer, 2022, 11, pp.022. Starting from the asymptotic kinematics of massless scalar fields near null infinity in any spacetime dimension, we build two higher-spin extensions of the Carrollian definition of the BMS group and its generalisations. The first extension exhibits conformal properties reminiscent of the singleton in Anti-de Sitter space. The second acts on the space of radiative solutions of the d'Alembert equation, i.e. on Sachs's representation of BMS, which we relate to the scalar massless Poincare representation and extend to any Carrollian manifold. The corresponding enveloping algebra is a higher-spin extension of BMS that can be interpreted as the asymptotic symmetry of a putative exotic higher-spin gravity theory around Minkowski spacetime. Along the way, we provide a pedagogical introduction to Carrollian geometry and its relation to BMS. (10.1007/JHEP11(2022)022)
DOI : 10.1007/JHEP11(2022)022
Random field ϕ$^{3}$ model and Parisi-Sourlas supersymmetry
- Kaviraj Apratim
- Trevisani Emilio
Journal of High Energy Physics, Springer, 2022, 2022 (08), pp.290. We use the RG framework set up in [1] to explore the ϕ$^{3}$ theory with a random field interaction. According to the Parisi-Sourlas conjecture this theory admits a fixed point with emergent supersymmetry which is related to the pure Lee-Yang CFT in two less dimensions. We study the model using replica trick and Cardy variables in d = 8 − ϵ where the RG flow is perturbative. Allowed perturbations are singlets under the S$_{n}$ symmetry that permutes the n replicas. These are decomposed into operators with different scaling dimensions: the lowest dimensional part, ‘leader’, controls the RG flow in the IR; the other operators, ‘followers’, can be neglected. The leaders are classified into: susy-writable, susy-null and non-susy-writable according to their mixing properties. We construct low lying leaders and compute the anomalous dimensions of a number of them. We argue that there is no operator that can destabilize the SUSY RG flow in d ≤ 8. This agrees with the well known numerical result for critical exponents of Branched Polymers (which are in the same universality class as the random field ϕ$^{3}$ model) that match the ones of the pure Lee-Yang fixed point according to dimensional reduction in all 2 ≤ d ≤ 8. Hence this is a second strong check of the RG framework that was previously shown to correctly predict loss of dimensional reduction in random field Ising model. (10.1007/JHEP08(2022)290)
DOI : 10.1007/JHEP08(2022)290
Parisi-Sourlas Supersymmetry in Random Field Models
- Kaviraj Apratim
- Rychkov Slava
- Trevisani Emilio
Physical Review Letters, American Physical Society, 2022, 129 (4), pp.045701. By the Parisi-Sourlas conjecture, the critical point of a theory with random field (RF) disorder is described by a supersymmeric (SUSY) conformal field theory (CFT), related to a <math display="inline"><mi>d</mi><mo>-</mo><mn>2</mn></math> dimensional CFT without SUSY. Numerical studies indicate that this is true for the RF <math display="inline"><msup><mi>ϕ</mi><mn>3</mn></msup></math> model but not for the RF <math display="inline"><msup><mi>ϕ</mi><mn>4</mn></msup></math> model in <math display="inline"><mi>d</mi><mo><</mo><mn>5</mn></math> dimensions. Here we argue that the SUSY fixed point is not reached because of new relevant SUSY-breaking interactions. We use a perturbative renormalization group in a judiciously chosen field basis, allowing systematic exploration of the space of interactions. Our computations agree with the numerical results for both cubic and quartic potential. (10.1103/PhysRevLett.129.045701)
DOI : 10.1103/PhysRevLett.129.045701
Flat JT Gravity and the BMS-Schwarzian
- Afshar Hamid
- Oblak Blagoje
Journal of High Energy Physics, Springer, 2022, 11, pp.172. We consider Minkowskian Jackiw-Teitelboim (JT) gravity in Bondi gauge at finite temperature, with non-zero vacuum energy. Its asymptotic symmetries span an extension of the warped Virasoro group, dubbed "BMS$_2$", which we investigate in detail. In particular, we show that this extension has a single coadjoint orbit when central charges are real and non-zero. The ensuing BMS-Schwarzian action has no saddle points, and only coincides with the boundary action functional of flat JT gravity up to a crucial dilatonic zero-mode that ensures the existence of a well-defined bulk variational principle. We evaluate the corresponding gravitational partition function, which turns out to be one-loop exact precisely thanks to the presence of such a zero-mode. (10.1007/JHEP11(2022)172)
DOI : 10.1007/JHEP11(2022)172
On the hydrodynamics of (2 + 1)-dimensional strongly coupled relativistic theories in an external magnetic field
- Amoretti Andrea
- Brattan Daniel K.
Mod.Phys.Lett.A, 2022, 37 (21), pp.2230010. In this paper, we review recent progress on relativistic hydrodynamics in (2 + 1) dimensions with an external magnetic field. We discuss the formalism allowing for momentum loss due to the explicit and spontaneous breaking of translation invariance by scalar operators. We also compare to some results from the gauge/gravity correspondence. (10.1142/S0217732322300105)
DOI : 10.1142/S0217732322300105
Return-time Lq -spectrum for equilibrium states with potentials of summable variation
- Abadi M
- Amorim V
- Chazottes J.-R
- Gallo S
Ergodic Theory and Dynamical Systems, Cambridge University Press (CUP), 2022, 43 (8), pp.2489-2515. Let $(X_k)_{k\geq 0}$ be a stationary and ergodic process with joint distribution $\mu$ where the random variables $X_k$ take values in a finite set $\mathcal{A}$. Let $R_n$ be the first time this process repeats its first $n$ symbols of output. It is well-known that $\frac{1}{n}\log R_n$ converges almost surely to the entropy of the process. Refined properties of $R_n$ (large deviations, multifractality, etc) are encoded in the return-time $L^q$-spectrum defined as \[ \EuScript{R}(q)=\lim_n\frac{1}{n}\log\int R_n^q \dd\mu\quad (q\in\R) \] provided the limit exists. We consider the case where $(X_k)_{k\geq 0}$ is distributed according to the equilibrium state of a potential $\varphi:\mathcal{A}^{\N}\to\R$ with summable variation, and we prove that \[ \EuScript{R}(q) = \begin{cases} P((1-q)\varphi) & \text{for}\;\; q\geq q_\varphi^*\\ \sup_\eta \int \varphi \dd\eta & \text{for}\;\; q<q_\varphi^{*} \end{cases} \] where $P((1-q)\varphi)$ is the topological pressure of $(1-q)\varphi$, the supremum is taken over all shift-invariant measures, and $q_\varphi^*$ is the unique solution of $P((1-q)\varphi) =\sup_\eta \int \varphi \dd\eta$. Unexpectedly, this spectrum does not coincide with the $L^q$-spectrum of $\mu_\varphi$, which is $P((1-q)\varphi)$, and does not coincide with the waiting-time $L^q$-spectrum in general. In fact, the return-time $L^q$-spectrum coincides with the waiting-time $L^q$-spectrum if and only if the equilibrium state of $\varphi$ is the measure of maximal entropy. As a by-product, we also improve the large deviation asymptotics of $\frac{1}{n}\log R_n$. (10.1017/etds.2022.40)
DOI : 10.1017/etds.2022.40
Global and local topological quantized responses from geometry, light, and time
- Le Hur Karyn
Physical Review B, American Physical Society, 2022, 105 (12), pp.125106. To describe a spin-<math><mfrac><mn>1</mn><mn>2</mn></mfrac></math> particle on the Bloch sphere with a radial magnetic field and topological states of matter from the reciprocal space, we introduce <math><mi>C</mi></math> square (<math><msup><mi>C</mi><mn>2</mn></msup></math>) as a local formulation of the global topological invariant. For the Haldane model on the honeycomb lattice, this <math><msup><mi>C</mi><mn>2</mn></msup></math> can be measured from the Dirac points through circularly polarized light related to the high-symmetry <math><mi>M</mi></math> point(s). For the quantum spin Hall effect and the Kane-Mele model, the <math><msub><mi mathvariant="double-struck">Z</mi><mn>2</mn></msub></math> topological number robust to interactions can be measured locally from a correspondence between the Pfaffian and light. We address a relation with a spin pump and the quantum spin Hall conductance. The analogy between light and magnetic nuclear resonance may be applied for imaging, among other applications. (10.1103/PhysRevB.105.125106)
DOI : 10.1103/PhysRevB.105.125106

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