Publications

2025

• Quadrupole forces between quark/gluon subsystems inside higher-spin particles
  
  • Kim June-Young
  • Kim Hyun-Chul
  Physical Review D, American Physical Society, 2025, 112 (7), pp.074014. We generalize the mechanical interpretation of the forces between quark and gluon subsystems, previously studied for the nucleon, to arbitrary higher-spin particles. For spin-0 and spin-1/2 particles, this force is characterized by the non-conserved $\bar{c}(t)$ form factor. However, such an interpretation has not yet been established for higher-spin particles due to the intricate structure of the non-conserved energy-momentum tensor (EMT) form factors. By performing a multipole expansion, we identify the physically meaningful combinations of the non-conserved covariant EMT form factors and provide them with a clear mechanical interpretation. (10.1103/r2t1-f4mc)
  DOI : 10.1103/r2t1-f4mc
• Bootstrapping frustrated magnets: the fate of the chiral ${\rm O}(N)\times {\rm O}(2)$ universality class
  
  • Reehorst Marten
  • Rychkov Slava
  • Sirois Benoit
  • van Rees Balt C
  SciPost Physics, SciPost Foundation, 2025, 18 (2), pp.060. We study multiscalar theories with $\text{O}(N) \times \text{O}(2)$ symmetry. These models have a stable fixed point in $d$ dimensions if $N$ is greater than some critical value $N_c(d)$. Previous estimates of this critical value from perturbative and non-perturbative renormalization group methods have produced mutually incompatible results. We use numerical conformal bootstrap methods to constrain $N_c(d)$ for $3 \leq d < 4$. Our results show that $N_c> 3.78$ for $d = 3$. This favors the scenario that the physically relevant models with $N = 2,3$ in $d=3$ do not have a stable fixed point, indicating a first-order transition. Our result exemplifies how conformal windows can be rigorously constrained with modern numerical bootstrap algorithms. (10.21468/SciPostPhys.18.2.060)
  DOI : 10.21468/SciPostPhys.18.2.060
• Backward DVCS on the pion in Sullivan processes
  
  • Castro Abigail Rodrigues
  • Mezrag Cedric
  • Chávez Jose M. Morgado
  • Pire Bernard
  Proceedings of Science, 2025, DIS2024, pp.258. The purpose of this work is to do a systematic feasibility study of measuring in backward region deeply virtual Compton scattering on the pion in Sullivan processes in the framework of collinear QCD factorization where pion to photon transition distribution amplitudes (TDAs) describe the photon content of the $\pi$ meson. Our approach employs TDAs based on the overlap of light front wave functions, using a previously developed pion light-front wave function and deriving a consistent model for the light front wave functions of the photon. This work is expected to lead us to an estimate of the cross-sections that could be measured in the future U.S. and China's electron-ion colliders. It will also provide a comparison with the forward Sullivan DVCS case, which gives access to pion GPDs and for which a strong signal is expected. (10.22323/1.469.0258)
  DOI : 10.22323/1.469.0258
• Topological Quantum Spin Hall Semimetals with Light
  
  • Le Hur Karyn
  Physical Review B, American Physical Society, 2025, 112 (7), pp.075120. We introduce a quantum spin Hall semimetal or Fermi liquid characterized with a Z2 topological invariant, measurable through circularly polarized light. We propose its engineering through two topological metallic band structures in crystals on the honeycomb lattice, with spin-orbit interaction, realizable through the interplay of a charge or spin density wave substrate and Zeeman effects, in between a quantum spin Hall and a quantum anomalous Hall insulator. These systems show topologically protected helical edge or photo-induced currents. (10.1103/d72s-m3rk)
  DOI : 10.1103/d72s-m3rk
• Long time behavior of a degenerate stochastic system modeling the response of a population face to environmental impacts
  
  • Collet Pierre
  • Ecotière Claire
  • Méléard Sylvie
  Electronic Communications in Probability, Institute of Mathematical Statistics (IMS), 2025, 30 (none). We study the asymptotics of a two-dimensional stochastic differential system with a degenerate diffusion matrix. This system describes the dynamics of a population where individuals contribute to the degradation of their environment through two different behaviors. We exploit the almost one-dimensional form of the dynamical system to compute explicitly the Freidlin-Wentzell action functional. That allows to give conditions under which the small noise regime of the invariant measure is concentrated around the equilibrium of the dynamical system having the smallest diffusion coefficient. (10.1214/24-ECP650)
  DOI : 10.1214/24-ECP650
• One-Dimensional Carrollian Fluids III: Global Existence and Weak Continuity in $L^\infty$
  
  • Petropoulos P. Marios
  • Schulz Simon
  • Taujanskas Grigalius
  J.Lond.Math.Soc., 2025, 111 (6), pp.e70186. The Carrollian fluid equations arise as the $c \to 0$ limit of the relativistic fluid equations and have recently experienced a surge of activity in the flat-space holography community. However, the rigorous mathematical well-posedness theory for these equations does not appear to have been previously studied. This paper is the third in a series in which we initiate the systematic analysis of the Carrollian fluid equations. In the present work we prove the global-in-time existence of bounded entropy solutions to the isentropic Carrollian fluid equations in one spatial dimension for a particular constitutive law ($\gamma = 3$). Our method is to use a vanishing viscosity approximation for which we establish a compensated compactness framework. Using this framework we also prove the compactness of entropy solutions in $L^\infty$, and establish a kinetic formulation of the problem. This global existence result in $L^\infty$ extends the $C^1$ theory presented in our companion paper ``One-Dimensional Carrollian Fluids II: $C^1$ Blow-up Criteria''. (10.1112/jlms.70186)
  DOI : 10.1112/jlms.70186
• Neural Projected Quantum Dynamics: a systematic study
  
  • Gravina Luca
  • Savona Vincenzo
  • Vicentini Filippo
  Quantum, Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften, 2025, 9, pp.1803. We address the challenge of simulating unitary quantum dynamics in large systems using Neural Quantum States, focusing on overcoming the computational instabilities and high cost of existing methods. This work offers a comprehensive formalization of the projected time-dependent Variational Monte Carlo (p-tVMC) method by thoroughly analyzing its two essential components: stochastic infidelity minimization and discretization of the unitary evolution. We investigate neural infidelity minimization using natural gradient descent strategies, identifying the most stable stochastic estimators and introducing adaptive regularization strategies that eliminate the need for manual adjustment of the hyperparameter along the dynamics. We formalize the specific requirements that p-tVMC imposes on discretization schemes for them to be efficient, and introduce four high-order integration schemes combining Taylor expansions, Padé approximants, and Trotter splitting to enhance accuracy and scalability. We benchmark our adaptive methods against a 2D Ising quench, matching state of the art techniques without manual tuning of hyperparameters. This work establishes p-tVMC as a highly promising framework for addressing complex quantum dynamics, offering a compelling alternative for researchers looking to push the boundaries of quantum simulations. (10.22331/q-2025-07-22-1803)
  DOI : 10.22331/q-2025-07-22-1803
• Quantum Gravity, Hydrodynamics and Emergent Cosmology: A Collection of Perspectives
  
  • Ben Achour Jibril
  • Benedetti Dario
  • Bojowald Martin
  • Brandenberger Robert
  • Butera Salvatore
  • Ferrero Renata
  • Giacomini Flaminia
  • Giesel Kristina
  • Goeller Christophe
  • Haas Tobias
  • Höhn Philipp A
  • Kirklin Joshua
  • Marchetti Luca
  • Oriti Daniele
  • Percacci Roberto
  • Pereira Antonio D
  • Pithis Andreas G.A
  • Sakellariadou Mairi
  • Steinhaus Sebastian
  • Thürigen Johannes
  General Relativity and Gravitation, Springer Verlag, 2025, 57 (1), pp.2. This collection of perspective pieces captures recent advancements and reflections from a dynamic research community dedicated to bridging quantum gravity, hydrodynamics, and emergent cosmology. It explores four key research areas: (a) the interplay between hydrodynamics and cosmology, including analog gravity systems; (b) phase transitions, continuum limits and emergent geometry in quantum gravity; (c) relational perspectives in gravity and quantum gravity; and (d) the emergence of cosmological models rooted in quantum gravity frameworks. Each contribution presents the distinct perspectives of its respective authors. Additionally, the introduction by the editors proposes an integrative view, suggesting how these thematic units could serve as foundational pillars for a novel theoretical cosmology framework termed "hydrodynamics on superspace". (10.1007/s10714-024-03335-4)
  DOI : 10.1007/s10714-024-03335-4
• Entropy and multiplicity of hadrons in the high energy limit within dipole cascade models
  
  • Kutak Krzysztof
  • Lökös Sándor
  Physical Review D, American Physical Society, 2025, 112 (9), pp.096017. We investigate and compare QCD dipole cascade models, the 1D Mueller dipole model, its high energy limit and its generalization that follows from studies of 1D systems with conformal symmetry. To address the ambiguity stemming from different definitions of the rapidity ranges in experimental measurements, we propose the entropy as the function of the logarithm of the average multiplicity, $S(\ln\langle n \rangle)$, as a universal observable. From the solutions of the models, we calculate both the entropy and the average charged particle multiplicity and compare to data measured in proton-proton collisions. We obtained these quantities directly from the measured multiplicity distributions and determine the model parameters via fits. We find that the generalized dipole model provides a significantly better description of the data than the 1D Mueller model. (10.1103/23wn-66np)
  DOI : 10.1103/23wn-66np
• Photon Antibunching in Single-Molecule Vibrational Sum-Frequency Generation
  
  • Kalarde Fatemeh Moradi
  • Munoz Carlos Sanchez
  • Feist Johannes
  • Galland Christophe
  Nanophoton., 2025, 14 (1), pp.59-73. Sum-frequency generation (SFG) allows for coherent upconversion of an electromagnetic signal and has applications in mid-infrared vibrational spectroscopy of molecules. Recent experimental and theoretical studies have shown that plasmonic nanocavities, with their deep sub-wavelength mode volumes, may allow to obtain vibrational SFG signals from a single molecule. In this article, we compute the degree of second order coherence ($g^{(2)}(0)$) of the upconverted mid-infrared field under realistic parameters and accounting for the anharmonic potential that characterizes vibrational modes of individual molecules. On the one hand, we delineate the regime in which the device should operate in order to preserve the second-order coherence of the mid-infrared source, as required in quantum applications. On the other hand, we show that an anharmonic molecular potential can lead to antibunching of the upconverted photons under coherent, Poisson-distributed mid-infrared and visible drives. Our results therefore open a path toward a new kind of bright and tunable source of indistinguishable single photons by leveraging ``vibrational blockade'' in a resonantly and parametrically driven molecule, without the need for strong light-matter coupling. (10.1515/nanoph-2024-0469)
  DOI : 10.1515/nanoph-2024-0469
• Fractons on curved spacetime in $2+1$ dimensions
  
  • Hartong Jelle
  • Palumbo Giandomenico
  • Pekar Simon
  • Pérez Alfredo
  • Prohazka Stefan
  SciPost Physics, SciPost Foundation, 2025, 18 (1), pp.022. We study dipole Chern-Simons theory with and without a cosmological constant in $2+1$ dimensions. We write the theory in a second order formulation and show that this leads to a fracton gauge theory coupled to Aristotelian geometry which can also be coupled to matter. This coupling exhibits the remarkable property of generalizing dipole gauge invariance to curved spacetimes, without placing any limitations on the possible geometries. We also use the second order formulation to construct a higher dimensional generalization of the action. Finally, for the $(2+1)$-dimensional Chern-Simons theory we find solutions and interpret these as electric monopoles, analyze their charges and argue that the asymptotic symmetries are infinite-dimensional. (10.21468/SciPostPhys.18.1.022)
  DOI : 10.21468/SciPostPhys.18.1.022
• The exact Wheeler-DeWitt equation for the scale-factor minisuperspace model
  
  • Kaimakkamis Eftychios
  • Partouche Hervé
  • Sil Karunava
  • Toumbas Nicolaos
  Classical and Quantum Gravity, IOP Publishing, 2025, 42 (11), pp.115003. We consider the classical minisuperspace model describing a closed, homogeneous and isotropic Universe, with a positive cosmological constant. Upon canonical quantization, the infinite number of possible operator orderings in the quantum Hamiltonian leads to distinct Wheeler-DeWitt equations for the wavefunction $\psi$ of the Universe. Similarly, ambiguity arises in the path-integral formulation of $\psi$, due to the infinite choices of path-integral measures for the single degree of freedom of the model. For each choice of path-integral measure, we determine the correct operator ordering of the quantum Hamiltonian and derive the exact form of the Wheeler-DeWitt equation, including all corrections in $\hbar$. Additionally, we impose Hermiticity of the Hamiltonian to deduce the Hilbert-space measure $\mu$, which appears in the definition of the Hermitian inner product. Remarkably, all quantum predictions can be expressed through the combination $\Psi=\sqrt{\mu}\, \psi$, which satisfies a universal Wheeler-DeWitt equation, independent of the initial path-integral prescription. This result demonstrates that all seemingly distinct quantum theories arising from different quantization schemes of the same classical model are fundamentally equivalent. (10.1088/1361-6382/add705)
  DOI : 10.1088/1361-6382/add705
• Lighting up the Photon Wigner Distribution via Dilepton Productions
  
  • Shi Yu
  • Chen Lin
  • Wei Shu-Yi
  • Xiao Bo-Wen
  Physics Letters B, Elsevier, 2025, 862, pp.139317. We present a systematic investigation of lepton pair production through photon-photon fusion processes in heavy-ion collisions. It is demonstrated that the dilepton production at a given impact parameter ($b_\perp$) with a fixed transverse momentum imbalance ($q_\perp$) can be factorized into a unified formula in terms of the Wigner photon distribution of heavy nuclei. We show that this framework provides a comprehensive description of all the relevant data from RHIC to the LHC, with a strong evidence that the quasi-real photon can be radiated not only from the nucleus as a whole, standing for the coherent contribution, but also from the sub-structures inside the nucleus, representing the incoherent contribution. Further predictions are made for the anisotropies in the correlations between $q_\perp$, $b_\perp$, and the dilepton transverse momentum ($P_\perp$). This will help us to constrain the photon Wigner distribution which plays a crucial role to study the gluonic matter of nucleus at small-$x$ through the diffractive photoproduction processes in heavy ion collision. (10.1016/j.physletb.2025.139317)
  DOI : 10.1016/j.physletb.2025.139317
• Heavy-quark corner of the Columbia plot from the center-symmetric Curci-Ferrari model
  
  • Surkau V. Tomas Mari
  • Reinosa Urko
  Physical Review D, American Physical Society, 2025, 112 (1), pp.014002. We investigate the heavy-quark corner of the Columbia plot using the gluon potential derived from the Curci-Ferrari extension of the Faddeev-Popov gauge fixing in the center-symmetric Landau gauge, as a proxy for the Polyakov loop potential. In line with the observation that Landau gauge couplings are not that large in the case of heavy-quark QCD, we consider a one-loop approximation and test its consistency by using various renormalization schemes while investigating the dependence of our results on the renormalization scale. We find that the main qualitative features of the phase structure in the heavy-quark regime are reproduced. Our results agree quantitatively with those of simulations to $10\%$ accuracy, which is the expected precision of the one-loop calculations in applications of the Curci-Ferrari model to Yang-Mills or heavy-quark QCD theories. (10.1103/7dx2-vmj6)
  DOI : 10.1103/7dx2-vmj6
• Complete definition of $N \rightarrow \Delta$ transition generalized parton distributions
  
  • Kim June-Young
  • Semenov-Tian-Shansky Kirill M
  • Won Ho-Yeon
  • Son Sangyeong
  • Weiss Christian
  Physical Review D, American Physical Society, 2025, 111 (11), pp.114010. We revisit the definition of the leading-twist chiral-even generalized parton distributions (GPDs) for $N \to \Delta$ baryon transitions. We identify and address deficiencies in previous definitions of the transition GPDs inspired by the transition form factors of the vector and axial-vector currents. Through systematic analysis of all possible covariant structures, respecting discrete symmetries and the baryon spinor equations of motion, we derive complete sets of independent structures for the transition matrix elements of the vector and axial-vector partonic operators. They contain additional structures proportional to the light-cone vector, corresponding to transition GPDs of vanishing first moment, which were not included in previous parametrizations. Their presence is confirmed independently by the light-front multipole expansion and the cross-channel SO(3) partial-wave analysis of the transition matrix elements. Our analysis provides a complete definition of the $N \to \Delta$ transition GPDs for use in theoretical and phenomenological studies. (10.1103/m4vj-bkqy)
  DOI : 10.1103/m4vj-bkqy
• Double DVCS amplitudes including kinematic twist-3 and 4 corrections
  
  • Martinez-Fernandez V.
  • Pire B.
  • Sznajder P.
  • Wagner J.
  Proceedings of Science, 2025, PoS(DIS2024) (PoS(DIS2024)), pp.205. Generalized parton distributions (GPDs) are off-forward matrix elements of quark and gluon operators that work as a window to the total angular momentum of partons and their transverse imaging (nucleon tomography). To access GPDs one needs to look into exclusive processes which are usually studied in a kinematic regime known as the Bj\"orken limit. In this limit, the photon virtualities are much larger than the hadron mass $M$, and the kick to the hadron measured by the Mandelstam's variable $t$. It turns out that this is not enough for the purposes of a precise GPD extraction and, in particular, of nucleon tomography for which measurements in a sizable range of $t$ are required. Deviation with respect to the Bj\"orken limit induces kinematic higher-twist corrections which enter the amplitudes with powers of $|t|/\mathbb{Q}^2$ and $M^2/\mathbb{Q}^2$, where $\mathbb{Q}^2$ denotes the scale of the process (basically, the sum of photon virtualities in the case of DDVCS). There are also corrections by the name of "genuine" higher twists which are a separate topic and are not the subject of this research study. In this manuscript, we present novel calculations of DDVCS amplitudes off a (pseudo-)scalar target including up to kinematic twist-4 corrections. These results are important for measuring DDVCS, DVCS and TCS through the Sullivan process and off helium-4 target at the future Electron-Ion Collider (EIC) and JLab experiments. Preliminary numerical estimates for the pion target are provided. (10.22323/1.469.0205)
  DOI : 10.22323/1.469.0205
• A note on non-Lorentzian duality symmetries
  
  • O'Connor Josh A
  • Pekar Simon
  Journal of High Energy Physics, Springer, 2025, 03, pp.084. We work out non-Lorentzian dual actions for electromagnetism and linearised gravity, both in the Carrollian and Galilean cases. This is done in the same way as for Lorentzian theories, by first constructing a parent action that reduces to a pair of dual actions. In the case of Maxwell theory, each pair of dual actions consists of the known `electric' and `magnetic' limits of the original theories, showing that these limits are related by an off-shell electromagnetic duality. We have obtained dualities between on one hand the non-Lorentzian contractions of linearised gravity in second-order form, and on the other hand the theories one obtains by gauging the corresponding kinematic algebras. In the Carrollian contraction, these dual actions reproduce the known `electric' and `magnetic' Carrollian theories of gravity, and we find a similar result in the Galilean case. (10.1007/JHEP03(2025)084)
  DOI : 10.1007/JHEP03(2025)084
• Near-extremal quantum cross-section for charged fields and superradiance
  
  • Betzios Panos
  • Papadoulaki Olga
  • Zhou Yanjun
  Journal of High Energy Physics, Springer, 2025, 11, pp.114. We study the scattering and absorption properties of charged scalar fields on a near-extremal Reissner-Nordström black hole background. We show that in this low-temperature regime the near-horizon throat experiences large quantum fluctuations, whose leading contribution is described by the one dimensional Schwarzian effective action, while the soft $U(1)$ gauge modes can only contribute to subleading order. We investigate the role of the leading quantum effects both inside and outside the superradiant regime. These effects result in an enhanced reflection coefficient within the superradiant regime, while causing a suppression in the non-superradiant regime. On the other hand, the absorption cross-section increases in both regimes. Additional physical features appear as kinks in the reflection coefficient and absorption cross-section plots, corresponding to the shutdown of absorption in the superradiant regime and of stimulated emission in the non-superradiant regime. (10.1007/JHEP11(2025)114)
  DOI : 10.1007/JHEP11(2025)114
• Strong-field ionization in particle-in-cell simulations
  
  • Mironov A.A
  • Gelfer E.G
  • Tupitsyn I.I
  • Beck A
  • Jirka M
  • Klimo O
  • Meuren S
  • Oberreit G
  • Smorodnikova T
  • Taïeb R
  • Weber S
  • Riconda C
  • Grech M
  • Popruzhenko S.V
  Physical Review E, American Physical Society (APS), 2025, 112 (5), pp.055202. The inclusion of the process of multiple ionization of atoms in high-intensity electromagnetic fields into particle-in-cell (PIC) codes applied to the simulation of laser-plasma interactions is a challenging task. In this paper, we first revisit ionization rates as given by the Smirnov-Chibisov and Perelomov-Popov-Terent'yev formulas within the paradigm of sequential tunnel ionization. We analyze the limit of validity and possible inconsistencies of this approach. We show that a strongly limiting factor to a precise description of ionization is the competing contribution of different sequential ionization processes. To solve this an algorithm is proposed that allows one to find the dominant nonsequential path of tunnel ionization and significantly improves the precision in simulations. This procedure is implemented in the PIC code SMILEI, and includes the dependence of the ionization rates on the magnetic quantum number of the level. The sensitivity to variations in the ionization model is studied via full simulations of the ionization of an argon target by an incident high-intensity laser pulse. Finally, we analyze generalizations of the Perelomov-Popov-Terent'yev rate developed to describe the barrier suppression ionization in high fields and discuss the necessity and possibility of including these extensions in PIC simulations. (10.1103/zlzb-kqtw)
  DOI : 10.1103/zlzb-kqtw
• Measurement of optical amplification and population dynamics using ultrafast XUV spectroscopy of N₂⁺
  
  • Danylo Rostyslav
  • Lambert Guillaume
  • Redkin Mykyta
  • Houard Aurélien
  • Zhang Xiang
  • Gao Shaofen
  • Xu Liang
  • Liu Y I
  • Liu Yi
  • Couairon Arnaud
  • Tikhonchuk Vladimir
  • Mysyrowicz André
  Optics Letters, Optical Society of America - OSA Publishing, 2025, 50 (19), pp.6205. We demonstrate a very strong laser gain in the near UV, at 391 nm, involving one- and two-photon transitions between initial and final levels of the transition. This opens the way to the realization of all-optical lasers at short wavelengths. The amplifying medium is N₂⁺ at low density, pumped by an intense laser source at a longer wavelength, i.e., 800 nm. It is probed by measuring with femtosecond precision the absorption of XUV high harmonics through the gas, displaying the evolution of the relevant electronic levels during the amplification process. We show the role of a third level forming a “V scheme” with the initial and final levels. (10.1364/OL.565942)
  DOI : 10.1364/OL.565942
• Electron-magnon dynamics triggered by an ultrashort laser pulse: A real-time dual GW study
  
  • Dasari Nagamalleswararao
  • Strand Hugo U R
  • Eckstein Martin
  • Lichtenstein Alexander I
  • Stepanov Evgeny A
  Physical Review B, American Physical Society, 2025, 111 (23), pp.235129. Ultrafast irradiation of correlated electronic systems triggers complex dynamics involving quasi-particle excitations, doublons, charge carriers, and spin fluctuations. To describe these effects, we develop an efficient non-equilibrium approach, dubbed D-$GW$, that enables a self-consistent treatment of local correlations within dynamical mean-field theory (DMFT) and spatial charge and spin fluctuations, that are accounted for simultaneously within a diagrammatic framework. The method is formulated in the real-time domain and provides direct access to single- and two-particle momentum- and energy-dependent response functions without the need for analytical continuation, which is required in Matsubara frequency-based approaches. We apply the D-$GW$ method to investigate the dynamics of a photo-excited extended Hubbard model, the minimal system that simultaneously hosts strong charge and spin fluctuations. Focusing on the challenging parameter regime near the Mott transition, we demonstrate that correlated metals and narrow-gap Mott insulators undergo distinct thermalization processes involving complex energy transfer between single-particle and collective electronic excitations. (10.1103/vglv-2rmv)
  DOI : 10.1103/vglv-2rmv
• Quantitative theory of magnetic properties of elemental praseodymium
  
  • Pourovskii Leonid V
  • Vishina Alena
  • Eriksson Olle
  • Katsnelson Mikhail I
  npj Computational Materials, Springer Nature, 2025, 11 (1), pp.326. Elemental Pr metal is unique among rare-earth elements in featuring a localized partially filled 4f shell without ordered magnetism. Experimental evidence attributes this absence of magnetism to a singlet crystal-field (CF) ground state of the Pr 4f 2 configuration. Here, we construct an effective magnetic Hamiltonian for dhcp Pr, by combining density-functional theory with dynamical mean-field theory, in the quasiatomic Hubbard-I approximation. Our calculations fully determine the CF potential and predict singlet CF ground states for both inequivalent Pr sites. The intersite exchange interactions, obtained from the magnetic force theorem, are insufficient to close the CF gap to the magnetic doublets. Hence, ab-initio theory is demonstrated to explain the non-magnetic state of elemental Pr. We also find that the singlet ground state remains robust preventing conventional magnetic orders at the (0001) surface of Pr. Nevertheless, the gap between the ground state and the lowest excited singlet is significantly reduced at the surface, opening the possibility for exotic two-dimensional multipolar orders to emerge within this two-singlet manifold. (10.1038/s41524-025-01803-2)
  DOI : 10.1038/s41524-025-01803-2
• Clifford-Dressed Variational Principles for Precise Loschmidt Echoes
  
  • Mello Antonio Francesco
  • Santini Alessandro
  • Collura Mario
  Physical Review A, American Physical Society, 2025, 111 (5), pp.052401. We extend the recently introduced Clifford dressed Time-Dependent Variational Principle (TDVP) to efficiently compute many-body wavefunction amplitudes in the computational basis. This advancement enhances the study of Loschmidt echoes, which generally require accurate calculations of the overlap between the evolved state and the initial wavefunction. By incorporating Clifford disentangling gates during TDVP evolution, our method effectively controls entanglement growth while keeping the computation of these amplitudes accessible. Specifically, it reduces the problem to evaluating the overlap between a Matrix Product State (MPS) and a stabilizer state, a task that remains computationally feasible within the proposed framework. To demonstrate the effectiveness of this approach, we first benchmark it on the one-dimensional transverse-field Ising model. We then apply it to more challenging scenarios, including a non-integrable next-to-nearest-neighbor Ising chain and a two-dimensional Ising model. Our results highlight the versatility and efficiency of the Clifford-augmented MPS, showcasing its capability to go beyond the evaluation of simple expectation values. This makes it a powerful tool for exploring various aspects of many-body quantum dynamics. (10.1103/PhysRevA.111.052401)
  DOI : 10.1103/PhysRevA.111.052401
• Towards an Interpretation of the First Measurements of Energy Correlators in the Quark-Gluon Plasma
  
  • Andres Carlota
  • Dominguez Fabio
  • Holguin Jack
  • Marquet Cyrille
  • Moult Ian
  Journal of High Energy Physics, Springer, 2025, 03, pp.166. Energy correlators have recently been proposed as a class of jet substructure observables that directly link experimental measurements of the asymptotic energy flux with the field theoretic description of the underlying microscopic dynamics. This link holds particular promise in heavy-ion physics, where both experimental measurements and theoretical interpretations are inherently complex. With recent measurements of energy correlators in proton-proton collisions, the first measurement of these observables on inclusive jets in heavy-ion collisions underscores the importance of a theoretical understanding of their behavior in this complex environment. In this manuscript, we extend our previous calculations to account for several effects necessary for a qualitative understanding of the behavior of energy correlators on inclusive jets in heavy-ion collisions. Through a semi-analytic approach implemented in a hydrodynamically expanding quark-gluon plasma (QGP), we account for medium-induced radiation with leading broadening effects, selection biases arising from energy loss, and a description of the confinement transition. Our results represent a crucial first step towards interpreting the measurements of energy correlators on inclusive jets in heavy-ion collisions, which marks a significant milestone in connecting heavy-ion experiment and fundamental quantum field theory, in the quest to disentangle the microscopic dynamics of the QGP. (10.1007/JHEP03(2025)166)
  DOI : 10.1007/JHEP03(2025)166
• Skydiving to Bootstrap Islands
  
  • Liu Aike
  • Simmons-Duffin David
  • Su Ning
  • van Rees Balt C
  Journal of High Energy Physics, Springer, 2025, 11, pp.003. We study families of semidefinite programs (SDPs) that depend nonlinearly on a small number of "external" parameters. Such families appear universally in numerical bootstrap computations. The traditional method for finding an optimal point in parameter space works by first solving an SDP with fixed external parameters, then moving to a new point in parameter space and repeating the process. Instead, we unify solving the SDP and moving in parameter space in a single algorithm that we call "skydiving". We test skydiving on some representative problems in the conformal bootstrap, finding significant speedups compared to traditional methods. (10.1007/JHEP11(2025)003)
  DOI : 10.1007/JHEP11(2025)003