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  • Journal article
    Gonzalez MC, de Rham C, Jaitly S, Pozsgay V, Tokareva Aet al., 2024,

    Positivity-causality competition: a road to ultimate EFT consistency constraints

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Gerhardinger M, Giblin Jr JT, Tolley AJ, Trodden Met al., 2024,

    Simulating a numerical UV completion of quartic Galileons

    , Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 109, ISSN: 1550-7998

    The Galileon theory is a prototypical effective field theory that incorporates the Vainshtein screening mechanism—a feature that arises in some extensions of general relativity, such as massive gravity. The Vainshtein effect requires that the theory contain higher order derivative interactions, which results in Galileons, and theories like them, failing to be technically well posed. While this is not a fundamental issue when the theory is correctly treated as an effective field theory, it nevertheless poses significant practical problems when numerically simulating this model. These problems can be tamed using a number of different approaches: introducing an active low-pass filter and/or constructing a UV completion at the level of the equations of motion, which controls the high momentum modes. These methods have been tested on cubic Galileon interactions, and have been shown to reproduce the correct low-energy behavior. Here we show how the numerical UV-completion method can be applied to quartic Galileon interactions, and present the first simulations of the quartic Galileon model using this technique. We demonstrate that our approach can probe physics in the regime of the effective field theory in which the quartic term dominates, while successfully reproducing the known results for cubic interactions.
  • Journal article
    Magueijo J, 2024,

    Dark matter and spacetime symmetry restoration

    , Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 109, ISSN: 1550-2368

    We examine local physics in the presence of global variables: variables associated with the whole of the spacelike surfaces of a foliation. These could be the (pseudo)constants of nature and their conjugate times, but our statements are more general. Interactions between the local and the global (for example, dependence of the local action on global times dual to constants) degrades full space-time diffeomorphism invariance down to spatial diffeomorphism invariance, and so an extra degree of freedom appears. When these presumably primordial global interactions switch off, the local action recovers full invariance and so the usual two gravitons, but a legacy matter component is left over, bearing the extra degree of freedom. Under the assumption that the preferred foliation is geodesic, this component behaves like dark matter, except that 3 of its 4 local degrees of freedom are frozen, forcing its rest frame to coincide with the preferred foliation. The nonfrozen degree of freedom (the number density of the effective fluid) is the survivor of the extra “graviton” present in the initial theory and keeps memory of all the past global interactions that took place in a given location in the preferred foliation. Such “painted-on” dark matter is best distinguished from the conventional one in situations where the preferred frame would be preposterous if all 4 degrees of freedom of dark matter were available. We provide one example: an outflowing halo of legacy matter with exact escape speed at each point and a very specific profile, surrounding a condensed structure made of normal matter.
  • Journal article
    Liu X, Santos JE, Wiseman T, 2024,

    New Well-Posed boundary conditions for semi-classical Euclidean gravity

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Chester SM, Pufu SS, Wang Y, Yin Xet al., 2024,

    Bootstrapping M-theory orbifolds

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Basile T, Joung E, Mkrtchyan K, Mojaza Met al., 2024,

    Spinor-helicity representations of particles of any mass in dS 4 and AdS 4 spacetimes

    , PHYSICAL REVIEW D, Vol: 109, ISSN: 2470-0010
  • Journal article
    Gautason FF, van Muiden J, 2024,

    One-loop quantization of Euclidean D3-branes in holographic backgrounds

    , Journal of High Energy Physics, Vol: 2024

    In this note we analyze the semi-classical quantization of D3-branes in three different holographic backgrounds in type IIB string theory. The first background is Euclidean AdS<inf>5</inf> with S<sup>1</sup>× S<sup>3</sup> boundary accompanied with a twist to preserve supersymmetry. We work out the spectrum of fluctuations around the classical D3-brane configuration, compute its one-loop partition function, and match to the non-perturbative correction to the superconformal index of N = 4 SYM. We then study Euclidean D3-branes in the Pilch-Warner geometry dual to the IR Leigh-Strassler fixed point of N = 1<sup>*</sup> with the aim to find non-perturbative corrections to its index. Finally we study Euclidean D3-branes in the non-geometric N = 2 J-fold background which is dual to the gauging of the 3D Gaiotto-Witten SCFT.
  • Journal article
    Abend S, Allard B, Alonso I, Antoniadis J, Araújo H, Arduini G, Arnold AS, Asano T, Augst N, Badurina L, Balaž A, Banks H, Barone M, Barsanti M, Bassi A, Battelier B, Baynham CFA, Beaufils Q, Belić A, Beniwal A, Bernabeu J, Bertinelli F, Bertoldi A, Biswas IA, Blas D, Boegel P, Bogojević A, Böhm J, Böhringer S, Bongs K, Bouyer P, Brand C, Brimis A, Buchmueller O, Cacciapuoti L, Calatroni S, Canuel B, Caprini C, Caramete A, Caramete L, Carlesso M, Carlton J, Casariego M, Charmandaris V, Chen Y-A, Chiofalo ML, Cimbri A, Coleman J, Constantin FL, Contaldi CR, Cui Y, Ros ED, Davies G, Rosendo EDP, Deppner C, Derevianko A, Rham CD, Roeck AD, Derr D, Di Pumpo F, Djordjevic GS, Döbrich B, Domokos P, Dornan P, Doser M, Drougakis G, Dunningham J, Duspayev A, Easo S, Eby J, Efremov M, Ekelof T, Elertas G, Ellis J, Evans D, Fadeev P, Fanì M, Fassi F, Fattori M, Fayet P, Felea D, Feng J, Friedrich A, Fuchs E, Gaaloul N, Gao D, Gardner S, Garraway B, Gauguet A, Gerlach S, Gersemann M, Gibson V, Giese E, Giudice GF, Glasbrenner EP, Gündoğan M, Haehnelt M, Hakulinen T, Hammerer K, Hanımeli ET, Harte T, Hawkins L, Hees A, Heise J, Henderson VA, Herrmann S, Hird TM, Hogan JM, Holst B, Holynski M, Hussain K, Janson G, Jeglič P, Jelezko F, Kagan M, Kalliokoski M, Kasevich M, Kehagias A, Kilian E, Koley S, Konrad B, Kopp J, Kornakov G, Kovachy T, Krutzik M, Kumar M, Kumar P, Lämmerzahl C, Landsberg G, Langlois M, Lanigan B, Lellouch S, Leone B, Poncin-Lafitte CL, Lewicki M, Leykauf B, Lezeik A, Lombriser L, Luis Lopez-Gonzalez J, Lopez Asamar E, Monjaraz CL, Luciano GG, Mahmoud MA, Maleknejad A, Krutzik M, Marteau J, Massonnet D, Mazumdar A, McCabe C, Meister M, Menu J, Messineo G, Micalizio S, Millington P, Milosevic M, Mitchell J, Montero M, Morley GW, Müller J, ioğlu ÖEM, Ni W-T, Noller J, Odžak S, Oi DKL, Omar Y, Pahl J, Paling S, Pandey S, Pappas G, Pareek V, Pasatembou E, Pelucchi E, Pereira dos Santos F, Piest B, Pikovski I, Pilaftsis A, Plunkett R, Poggiani R, Prevedelli M, Pupet al., 2024,

    Terrestrial very-long-baseline atom interferometry: workshop summary

    , AVS Quantum Science, Vol: 6, ISSN: 2639-0213

    This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more kilometer--scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions.
  • Journal article
    Mentasti G, Contaldi CR, Peloso M, 2024,

    Probing the galactic and extragalactic gravitational wave backgrounds with space-based interferometers

    , Journal of Cosmology and Astroparticle Physics, Vol: 2024, ISSN: 1475-7516

    We employ the formalism developed in [1] and [2] to study the prospect of detecting an anisotropic Stochastic Gravitational Wave Background (SGWB) with the Laser Interferometer Space Antenna (LISA) alone, and combined with the proposed space-based interferometer Taiji. Previous analyses have been performed in the frequency domain only. Here, we study the detectability of the individual coefficients of the expansion of the SGWB in spherical harmonics, by taking into account the specific motion of the satellites. This requires the use of time-dependent response functions, which we include in our analysis to obtain an optimal estimate of the anisotropic signal. We focus on two applications. Firstly, the reconstruction of the anisotropic galactic signal without assuming any prior knowledge of its spatial distribution. We find that both LISA and LISA with Taiji cannot put tight constraints on the harmonic coefficients for realistic models of the galactic SGWB. We then focus on the discrimination between a galactic signal of known morphology but unknown overall amplitude and an isotropic extragalactic SGWB component of astrophysical origin. In this case, we find that the two surveys can confirm, at a confidence level ≳ 3σ, the existence of both the galactic and extragalactic background if both have amplitudes as predicted in standard models. We also find that, in the LISA-only case, the analysis in the frequency domain (under the assumption of a time average of data taken homogeneously across the year) provides a nearly identical determination of the two amplitudes as compared to the optimal analysis.
  • Journal article
    Shi D, Shang F, Chen B, Expert P, Lü L, Stanley HE, Lambiotte R, Evans TS, Li Ret al., 2024,

    Local dominance unveils clusters in networks

    , Communications Physics, Vol: 7, ISSN: 2399-3650

    Clusters or communities can provide a coarse-grained description of complex systems at multiple scales, but their detection remains challenging in practice. Community detection methods often define communities as dense subgraphs, or subgraphs with few connections in-between, via concepts such as the cut, conductance, or modularity. Here we consider another perspective built on the notion of local dominance, where low-degree nodes are assigned to the basin of influence of high-degree nodes, and design an efficient algorithm based on local information. Local dominance gives rises to community centers, and uncovers local hierarchies in the network. Community centers have a larger degree than their neighbors and are sufficiently distant from other centers. The strength of our framework is demonstrated on synthesized and empirical networks with ground-truth community labels. The notion of local dominance and the associated asymmetric relations between nodes are not restricted to community detection, and can be utilised in clustering problems, as we illustrate on networks derived from vector data.
  • Journal article
    Alday LF, Chester SM, Hansen T, Zhong D-Let al., 2024,

    The AdS Veneziano amplitude at small curvature

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Hanany A, Kumaran G, Li C, Liu D, Sperling Met al., 2024,

    Actions on the quiver: discrete quotients on the Coulomb branch

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Hull CM, 2024,

    Magnetic charges for the graviton

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Conference paper
    Tseytlin AA, 2024,

    AdS/CFT, Wilson loops and M2-branes

    We discuss testing AdS/CFT correspondence between U(N)<inf>k</inf> × U(N)<inf>-k</inf> Chern-Simons-matter 3d gauge theory and M-theory in AdS<inf>4</inf> × S<sup>7</sup>/Z<inf>k</inf> background. We show that the quantum M2 brane partition function expanded near the corresponding classical solution matches the localization predictions on the gauge theory side in the case of BPS Wilson loop expectation value and instanton corrections to free energy.
  • Journal article
    Albertini E, Dowker F, Nasiri A, Zalel Set al., 2024,

    In-in correlators and scattering amplitudes on a causal set

    , Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 109, ISSN: 1550-2368

    Causal set theory is an approach to quantum gravity in which spacetime is fundamentally discrete at the Planck scale and takes the form of an irregular Lorentzian lattice, or “causal set,” from which continuum spacetime emerges in a large-scale (low-energy) approximation. In this work, we present new developments in the framework of interacting quantum field theory on causal sets. We derive a diagrammatic expansion for in-in correlators in local scalar field theories with finite polynomial interactions. We outline how these same correlators can be computed using the double-path integral, which acts as a generating functional for the in-in correlators. We modify the in-in generating functional to obtain a generating functional for in-out correlators. We define a notion of scattering amplitudes on causal sets with noninteracting past and future regions and verify that they are given by 𝑆-matrix elements (matrix elements of the time-evolution operator). We describe how these formal developments can be implemented to compute early Universe observables under the assumption that spacetime is fundamentally discrete.
  • Journal article
    de Rham C, Giblin JT, Tolley AJ, 2024,

    Scalar radiation with a quartic Galileon

    , Physical Review D, Vol: 109, ISSN: 2470-0010

    The class of Galileon scalar fields theories encapsulate the Vainshtein screening mechanism, which is characteristic of a large range of infrared modified theories of gravity. Such theories can lead to testable departures from general relativity through fifth forces and new scalar modes of gravitational radiation. However, the inherent nonlinearity of the Vainshtein mechanism has limited analytic attempts to describe Galileon theories with both cubic and quartic interactions. To improve on this, we perform direct numerical simulations of the quartic Galileon model for a rotating binary source and infer the power spectrum of given multipoles. To tame numerical instabilities we utilize a low-pass filter, extending previous work on the cubic Galileon. Our findings show that the multipole expansion is well defined and under control. Moreover, our results confirm that despite being a nonlinear scalar, the dominant Galileon radiation is quadrupole, and we find a new scaling behavior deep inside the Vainshtein region.
  • Journal article
    Alday LF, Chester SM, Dorigoni D, Green MB, Wen Cet al., 2024,

    Relations between integrated correlators in <i>N</i>=4 supersymmetric Yang-Mills theory

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Ghoderao PS, Rajantie A, 2024,

    Curvature perturbations from preheating with scale dependence

    , Journal of Cosmology and Astroparticle Physics, Vol: 2024, ISSN: 1475-7516

    We extend the formalism to calculate non-Gaussianity of primordial curvature perturbations produced by preheating in the presence of a light scalar field. The calculation is carried out in the separate universe approximation using the non-perturbative delta N formalism and lattice field theory simulations. Initial conditions for simulations are drawn from a statistical ensemble determined by modes that left the horizon during inflation, with the time-dependence of Hubble rate during inflation taken into account. Our results show that cosmic variance, i.e., the contribution from modes with wavelength longer than the size of the observable universe today, plays a key role in determining the dominant contribution. We illustrate our formalism by applying it to an observationally-viable preheating model motivated by non-minimal coupling to gravity, and study its full parameter dependence.
  • Journal article
    Colas T, de Rham C, Kaplanek G, 2024,

    Decoherence out of fire: purity loss in expanding and contracting universes

    , JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, ISSN: 1475-7516
  • Journal article
    Genolini PB, Gauntlett JP, Jiao Y, Luescher A, Sparks Jet al., 2024,

    Localization and attraction

    , The Journal of High Energy Physics, Vol: 2024, ISSN: 1029-8479

    We use equivariant localization to construct of-shell entropy functions for supersymmetric black holes in N = 2, D = 4 gauged supergravity coupled to matter. This allowsone to compute the black hole entropy without solving the supergravity equations of motionand provides a novel generalization of the attractor mechanism. We consider magneticallycharged black holes in AdS4 which have an AdS2 × M2 near horizon geometry, where M2 isa sphere or a spindle, and we also obtain entropy functions for ungauged supergravity as asimple corollary. We derive analogous results for black strings and rings in D = 5 supergravitywhich have an AdS3 × M2 near horizon geometry, and in this setting we derive an of-shellexpression for the central charge of the dual N = (0, 2), d = 2 SCFT.
  • Journal article
    Mentasti G, Contaldi CR, 2024,

    Observing gravitational waves with solar system astrometry

    , Journal of Cosmology and Astroparticle Physics, Vol: 2024, ISSN: 1475-7516

    The subtle influence of gravitational waves on the apparent positioning of celestial bodies offers novel observational windows [1,2,3,4]. We calculate the expected astrometric signal induced by an isotropic Stochastic Gravitational Wave Background (SGWB) in the short distance limit. Our focus is on the resultant proper motion of Solar System objects, a signal on the same time scales addressed by Pulsar Timing Arrays (PTA). We derive the corresponding astrometric deflection patterns, finding that they manifest as distinctive dipole and quadrupole correlations or, in some cases, may not be present. Our analysis encompasses both Einsteinian and non-Einsteinian polarisations. We estimate the upper limits for the amplitude of SGWBs that could be obtained by tracking the proper motions of large numbers of solar system objects such as asteroids. We find that for SGWBs with negative spectral indices, such as that generated by Super Massive Black Hole Binaries (SMBHB), the constraints from these observations could rival those from PTAs. With the Gaia satellite and the Vera C. Rubin Observatory poised to track an extensive sample of asteroids — ranging from Script O(105) to Script O(106), we highlight the significant future potential for similar surveys to contribute to our understanding of the SGWB.
  • Journal article
    Carrillo González M, 2024,

    Bounds on EFT’s in an expanding universe

    , Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 109, ISSN: 1550-2368

    We find bounds on the Wilson coefficients of effective field theories (EFTs) living in a universe undergoing expansion by requiring that its modes do not propagate further than a minimally coupled photon by a resolvable amount. To do so, we compute the spatial shift suffered by the EFT modes at a fixed time slice within the WKB approximation and the regime of validity of the EFT. We analyze the bounds arising on shift-symmetric scalars and curved space generalizations of Galileons.
  • Journal article
    Hull CM, 2024,

    Covariant action for self-dual <i>p</i>-form gauge fields in general spacetimes

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Isichei R, Magueijo J, 2024,

    Unimodular proca theory: breaking the U(1) gauge symmetry of unimodular gravity via a mass term

    , European Physical Journal C: Particles and Fields, Vol: 84, ISSN: 1124-1861

    We study the Hamiltonian structure ofunimodular-like theories, where the cosmological constant(or other supposed constants of nature) are demoted fromfixed parameters to classical constants of motion. No newlocal degrees of freedom are present as a result of a U(1)gauge invariance of the theory. Hamiltonian analysis of theaction reveals that the only possible gauge fixing that canbe enforced is setting the spatial components of the fourvolume time vector T i ≈ 0. As a consequence of this, thegauge-fixed unimodular path integral is equivalent to the minisuperspace unimodular path integral. However, should webreak the U(1) gauge invariance, two things happen: a massless propagating degree of freedom appears, and the (gaugeinvariant) zero-mode receives modified dynamics. The implications are investigated, with the phenomenology dependingcrucially on the target “constant”.
  • Journal article
    Beccaria M, Tseytlin AA, 2024,

    Large N expansion of superconformal index of k=1 ABJM theory and semiclassical M5 brane partition function

    , NUCLEAR PHYSICS B, Vol: 1001, ISSN: 0550-3213
  • Journal article
    Karapetyan M, Manvelyan R, Mkrtchyan K, 2024,

    On correlation functions of higher-spin currents in arbitrary dimensions <i>d</i> > 3

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Chester SM, Su N, 2024,

    Bootstrapping Deconfined Quantum Tricriticality

    , PHYSICAL REVIEW LETTERS, Vol: 132, ISSN: 0031-9007
  • Journal article
    Skrzypek T, Tseytlin AA, 2024,

    On AdS/CFT duality in the twisted sector of string theory on <i>AdS</i><sub>5</sub> x <i>S</i><SUP>5</SUP><i>/</i>Z<sub>2</sub> orbifold background

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Hulik O, Malek E, Valach F, Waldram Det al., 2024,

    Y-algebroids and <i>E</i><sub>7(7)</sub> x R<SUP>+</SUP>-generalised geometry

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Evnin O, Joung E, Mkrtchyan K, 2024,

    Democratic Lagrangians from topological bulk

    , PHYSICAL REVIEW D, Vol: 109, ISSN: 2470-0010

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