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  • Journal article
    Viegas E, Evans T, Viegas E, Evans TSet al., 2024,

    The Behavioural House Indicator: a faster and real time small-area indicative deprivation measure for England

    , Environment and Planning B: Urban Analytics and City Science, ISSN: 2399-8083

    Researchers have been long preoccupied with the measuring and monitoring of economic and social deprivation at small scales, neighbourhood, level in order to provide official government agencies and policy makers with more precise data insights. Whist valuable methodologies have been developed, the exercise of data collection associated with these methods tends to be expensive, time consuming, published infrequently with significant time delays, and subject to recurring changes to methodology. Here, we propose a novel method based on a straightforward methodology and data sources to generate a faster and real time indicator for deprivation at different scaling, small to larger areas. The results of our work show that our method provides a consistent view of deprivation across the regions of England and Wales, which are in line with the other indexes, but also highlight specific flash points of deep rural and highly dense urban deprivation areas that are not well captured by existing indexes. Our method is intended to aid researchers and policy makers by complementing existing but infrequent indexes.
  • Journal article
    Babak S, Falxa M, Franciolini G, Pieroni Met al., 2024,

    Forecasting the sensitivity of pulsar timing arrays to gravitational wave backgrounds

    , Physical Review B, Vol: 110, ISSN: 2469-9950

    Pulsar timing array (PTA) observations hinted towards the existence of a stochastic gravitational wave background (SGWB) in the nHz frequency band. Still, the nature of the SGWB signal cannot be confidently inferred from current data, and the leading explanation invokes mergers of supermassive black holes. If confirmed, such discovery would not only represent a turning point in our understanding of astrophysics, but it may severely limit the capability of searching for additional cosmological sources in the nHz frequency range. In this work, we build a simple framework to forecast the sensitivity of future pulsar timing array configurations and assess the parameter estimation of SGWB, which could consist of several contributions. We release the python code fastpta, implementing this framework and ready to use.
  • Journal article
    Babak S, Falxa M, Franciolini G, Pieroni Met al., 2024,

    Forecasting the sensitivity of pulsar timing arrays to gravitational wave backgrounds

    , PHYSICAL REVIEW D, Vol: 110, ISSN: 2470-0010
  • Journal article
    Arav I, Gauntlett JP, Jiao Y, Roberts MM, Rosen Cet al., 2024,

    Superconformal monodromy defects in N=4 SYM andLS theory

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

    We study type IIB supergravity solutions that are dual to two-dimensionalsuperconformal defects in d = 4 SCFTs which preserve N = (0, 2) supersymmetry. Weconsider solutions dual to defects in N = 4 SYM theory that have non-trivial monodromy forU(1)3 ⊂ SO(6) global symmetry and we also allow for the possibility of conical singularities.In addition, we consider the addition of fermionic and bosonic mass terms that have nontrivial dependence on the spatial directions transverse to the defect, while preserving thesuperconformal symmetry of the defect. We compute various physical quantities including thecentral charges of the defect expressed as a function of the monodromy, the on-shell action aswell as associated supersymmetric Rényi entropies. Analogous computations are carried outfor superconformal defects in the N = 1, d = 4 Leigh-Strassler SCFT. We also show thatthe defects of the two SCFTs are connected by a line of bulk marginal mass deformationsand argue that they are also related by bulk RG fow.
  • Journal article
    Acharya B, Alexandre J, Behera SC, Benes P, Bergmann B, Bertolucci S, Bevan A, Brancaccio R, Branzas H, Burian P, Campbell M, Cecchini S, Cho YM, de Montigny M, De Roeck A, Ellis JR, Fairbairn M, Felea D, Frank M, Gould O, Hays J, Hirt AM, Ho DL-J, Hung PQ, Janecek J, Kalliokoski M, Lacarrere DH, Leroy C, Levi G, Margiotta A, Maselek R, Maulik A, Mauri N, Mavromatos NE, Millward L, Mitsou VA, Musumeci E, Ostrovskiy I, Ouimet P-P, Papavassiliou J, Patrizii L, Pavalas GE, Pinfold JL, Popa LA, Popa V, Pozzato M, Pospisil S, Rajantie A, de Austri RR, Sahnoun Z, Sakellariadou M, Sakurai K, Sarkar S, Semenoff G, Shaa A, Sirri G, Sliwa K, Soluk R, Spurio M, Staelens M, Suk M, Tenti M, Togo V, Tuszynski JA, Upreti A, Vento V, Vives Oet al., 2024,

    MoEDAL Search in the CMS Beam Pipe for Magnetic Monopoles Produced via the Schwinger Effect

    , PHYSICAL REVIEW LETTERS, Vol: 133, ISSN: 0031-9007
  • Journal article
    Seibold FK, Tseytlin AA, 2024,

    Scattering on the supermembrane

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Gill AS, Benton SJ, Damaren CJ, Everett SW, Fraisse AA, Hartley JW, Harvey D, Holder B, Huff EM, Jauzac M, Jones WC, Lagattuta D, Leung JSY, Li L, Luu TVT, Massey R, McCleary JE, Nagy JM, Netterfield CB, Paracha E, Redmond SF, Rhodes JD, Robertson A, Romualdez LJ, Schmoll J, Shaaban MM, Sirks EL, Vassilakis GN, Vitorelli AZet al., 2024,

    SuperBIT Superpressure Flight Instrument Overview and Performance: Near-diffraction-limited Astronomical Imaging from the Stratosphere

    , Astronomical Journal, Vol: 168, ISSN: 0004-6256

    SuperBIT was a 0.5 m near-UV to near-infrared wide-field telescope that launched on a NASA superpressure balloon into the stratosphere from New Zealand for a 45-night flight. SuperBIT acquired multiband images of galaxy clusters to study the properties of dark matter using weak gravitational lensing. We provide an overview of the instrument and its various subsystems. We then present the instrument performance from the flight, including the telescope and image stabilization system, the optical system, the power system, and the thermal system. SuperBIT successfully met the instrument’s technical requirements, achieving a telescope pointing stability of 0.″34 ± 0.″10, a focal plane image stability of 0.″055 ± 0.″027, and a point-spread function FWHM of ∼0.″35 over 5-minute exposures throughout the 45-night flight. The telescope achieved a near-diffraction-limited point-spread function in all three science bands (u, b, and g). SuperBIT served as a pathfinder to the GigaBIT observatory, which will be a 1.34 m near-UV to near-infrared balloon-borne telescope.
  • Journal article
    Etkin A, Magueijo J, Rassouli F-S, 2024,

    Vortices, topology and time

    , Physics Letters B: Nuclear Physics and Particle Physics, Vol: 855, ISSN: 0370-2693

    We relate physical time with the topology of magnetic field vortices. We base ourselves on a formulation of unimodular gravity where the cosmological constant Λ appears as the canonical dual to a variable which on-shell becomes four-volume time. If the theory is restricted to a topological axionic form (viz. a parity-odd product of an electric and a magnetic field), such a time variable becomes the spatial integral of the Chern-Simons density. The latter equates to helicity, so that unimodular time is transmuted into the linking number of the vortices of the topological magnetic field, times their flux. With the added postulate that this flux is a universal constant, the flow of time can thus be interpreted as the progressive weaving of further links between magnetic field vortices, each link providing a quantum of time with value related to the fixed flux. Non-abelian extensions, and targetting parameters other than Λ are briefly examined, exposing different types of vortices and a possible role for inter-linking leading to new phenomenology.
  • Journal article
    Jiang H, Tseytlin AA, 2024,

    On co-dimension 2 defect anomalies in <i>N</i>=4 SYM and (2,0) theory via brane probes in AdS/CFT

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Gkountoumis G, Hull C, Vandoren S, 2024,

    Exact moduli spaces for N=2, <i>D</i>=5 freely acting orbifolds

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Hull C, Hutt ML, Lindstrom U, 2024,

    Charges and topology in linearised gravity

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

    Simulating a numerical UV completion of quartic Galileons

    , PHYSICAL REVIEW D, Vol: 109, ISSN: 2470-0010
  • 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
    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
    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
    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
    Shi D, Shang F, Chen B, Expert P, Lü L, Stanley HE, Lambiotte R, Evans TS, Li R, Shang F, Chen B, Expert P, Lü L, Yang A, 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
    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)k × U(N)-k Chern-Simons-matter 3d gauge theory and M-theory in AdS4 × S7/Zk 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
  • 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
    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
    Lehners J-L, Stelle KS, 2024,

    Higher-order gravity, finite action, and a safe beginning for the universe

    , European Physical Journal Plus, Vol: 139, ISSN: 2190-5444

    General relativity allows for inhomogeneous and anisotropic universes with finite action. By contrast, in quadratic gravity such solutions obtain infinite action and are thus eliminated. What remains are homogeneous and isotropic solutions undergoing accelerated expansion, thereby automatically inducing an early inflationary phase. In this manner, semi-classical consistency may explain some of the basic, coarse-grained features of the early universe. This includes suitable initial conditions for the second law of thermodynamics, in the spirit of the Weyl curvature hypothesis. We note that quadratic gravity is a renormalisable theory and may admit an asymptotically safe regime at high energies, rendering the theory trustworthy to high energies. We also comment on theories containing curvature terms up to infinite derivative order, and on the contrast with no-boundary initial conditions.
  • 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
    Ghoderao PS, Rajantie A, 2024,

    Curvature perturbations from preheating with scale dependence

    , JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, ISSN: 1475-7516
  • Journal article
    Figueroa DG, Pieroni M, Ricciardone A, Simakachorn Pet al., 2024,

    Cosmological Background Interpretation of Pulsar Timing Array Data

    , PHYSICAL REVIEW LETTERS, Vol: 132, ISSN: 0031-9007

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