Publications

Search or filter publications

Filter by type:

Filter by publication type

Filter by year:

to

Results

  • Showing results for:
  • Reset all filters

Search results

  • Journal article
    Bourget A, Grimminger JF, Hanany A, Kalveks R, Zhong Zet al., 2022,

    Higgs branches of U/SU quivers via brane locking

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Baker T, Calcagni G, Chen A, Fasiello M, Lombriser L, Martinovic K, Pieroni M, Sakellariadou M, Tasinato G, Bertacca D, Saltas IDet al., 2022,

    Measuring the propagation speed of gravitational waves with LISA

    , JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, ISSN: 1475-7516
  • Journal article
    Bourget A, Dancer A, Grimminger JF, Hanany A, Zhong Zet al., 2022,

    Partial implosions and quivers

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Erickson CW, Leung R, Stelle KS, 2022,

    Higgs Effect Without Lunch

    , Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, ISSN: 1364-503X

    Reduction in effective spacetime dimensionality can occur in field-theorymodels more general than the widely studied dimensional reductions based ontechnically consistent truncations. Situations where wavefunction factorsdepend nontrivially on coordinates transverse to the effective lower dimensioncan give rise to unusual patterns of gauge symmetry breaking. Leading-ordergauge modes can be left massless, but naturally occurring Stueckelberg modescan couple importantly at quartic order and higher, thus generating a "covert"pattern of gauge symmetry breaking. Such a situation is illustrated in afive-dimensional model of scalar electrodynamics in which one spatial dimensionis taken to be an interval with Dirichlet/Robin boundary conditions on opposingends. This simple model illuminates a mechanism which also has been found ingravitational braneworld scenarios.
  • Journal article
    Evans T, Chen B, Evans TS, Chen Bet al., 2022,

    Linking the network centrality measures closeness and degree

    , Communications Physics, Vol: 5, Pages: 1-11, ISSN: 2399-3650

    Measuring the importance of nodes in a network with a centrality measure is an core task in any network application. There many measures available and it is speculated that many encode similar information. We give an explicit non-linear relationship between two of the most popular measures of node centrality: degree and closeness. Based on a shortest-path tree approximation, we give an analytic derivation that shows the inverse ofcloseness is linearly dependent on the logarithm of degree. We show that our hypothesis works well for a range of networks produced from stochastic network models and for networks derived from 130 real-world data sets. We connect our results with previous results for other network distance scales such as average distance. Our results imply that measuring closeness is broadly redundant unless our relationship is used to remove the dependence on degree from closeness. The success of our relationship suggests that most networks can be approximated by shortest-path spanning trees which are all statistically similar two or more steps away from their root nodes.
  • Journal article
    Mylova M, Moschou M, Afshordi N, Magueijo Jet al., 2022,

    Non-gaussian signatures of a thermal big bang

    , Journal of Cosmology and Astroparticle Physics, Vol: 2022, Pages: 1-25, ISSN: 1475-7516

    What if Big Bang was hot from its very inception? This is possible in a bimetric theory where the source of fluctuations is thermal, requiring the model to live on a critical boundary in the space of parameters and can be realized when an anti-DBI brane moves within an EAdS2 ×E3 geometry. This setup renders the model unique, with sharp predictions for the scalar spectral index and its running. We investigate the non-Gaussian signatures of this thermal bimetric model, or "bi-thermal" for short. We adapt the standard calculation of non-Gaussianities for P(X,ϕ) models to the thermal nature of the model, emphasising how the bi-thermal peculiarities affect the calculation and alter results. This leads to precise predictions for the shape and amplitude of the three-point function of the bi-thermal model (at tree-level): flocalNL = -3/2 and fequilNL = -2 + 4 √(3)π/9 ≃ 0.4. We also discover a new shape of flattened non-gaussianity ∝ (k1 + k2 - k3)-3/2 + permutations, which is expected due to the excited thermal initial conditions. These results, along with our earlier predictions for the scalar power spectrum, provide sharp targets for the future generation of cosmological surveys.
  • Journal article
    Fumagalli J, Pieroni M, Renaux-Petel S, Witkowski LTet al., 2022,

    Detecting primordial features with LISA

    , JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, ISSN: 1475-7516
  • Journal article
    Addazi A, Alvarez-Muniz J, Alves Batista R, Amelino-Camelia G, Antonelli V, Arzano M, Asorey M, Atteia J-L, Bahamonde S, Bajardi F, Ballesteros A, Baret B, Barreiros DM, Basilakos S, Benisty D, Birnholtz O, Blanco-Pillado JJ, Blas D, Bolmont J, Boncioli D, Bosso P, Calcagni G, Capozziello S, Carmona JM, Cerci S, Chernyakova M, Clesse S, Coelho JAB, Colak SM, Cortes JL, Das S, D'Esposito V, Demirci M, Di Luca MG, di Matteo A, Dimitrijevic D, Djordjevic G, Prester DD, Eichhorn A, Ellis J, Escamilla-Rivera C, Fabiano G, Franchino-Vinas SA, Frassino AM, Frattulillo D, Funk S, Fuster A, Gamboa J, Gent A, Gergely LA, Giammarchi M, Giesel K, Glicenstein J-F, Gracia-Bondia J, Gracia-Ruiz R, Gubitosi G, Guendelman E, Gutierrez-Sagredo I, Haegel L, Heefer S, Held A, Herranz FJ, Hinderer T, Illana JI, Ioannisian A, Jetzer P, Joaquim FR, Kampert K-H, Uysal AK, Katori T, Kazarian N, Kerszberg D, Kowalski-Glikman J, Kuroyanagi S, Lammerzahl C, Said JL, Liberati S, Lim E, Lobo IP, Lopez-Moya M, Luciano GG, Manganaro M, Marciano A, Martin-Moruno P, Martinez M, Martinez M, Martinez-Huerta H, Martinez-Mirave P, Masip M, Mattingly D, Mavromatos N, Mazumdar A, Mendez F, Mercati F, Micanovic S, Mielczarek J, Miller AL, Milosevic M, Minic D, Miramonti L, Mitsou VA, Moniz P, Mukherjee S, Nardini G, Navas S, Niechciol M, Nielsen AB, Obers NA, Oikonomou F, Oriti D, Paganini CF, Palomares-Ruiz S, Pasechnik R, Pasic V, de los Heros CP, Pfeifer C, Pieroni M, Piran T, Platania A, Rastgoo S, Relancio JJ, Reyes MA, Ricciardone A, Risse M, Rodriguez Frias MD, Rosati G, Rubiera-Garcia D, Sahlmann H, Sakellariadou M, Salamida F, Saridakis EN, Satunin P, Schiffer M, Schussler F, Sigl G, Sitarek J, Sola Peracaula J, Sopuerta CF, Sotiriou TP, Spurio M, Staicova D, Stergioulas N, Stoica S, Striskovic J, Stuttard T, Cerci DS, Tavakoli Y, Ternes CA, Terzic T, Thiemann T, Tinyakov P, Torri MDC, Tortola M, Trimarelli C, Trzesniewski T, Tureanu A, Urban FR, Vagenas EC, Vernieri D, Vitagliano V, Wallet J-C Zet al., 2022,

    Quantum gravity phenomenology at the dawn of the multi-messenger era-A review

    , PROGRESS IN PARTICLE AND NUCLEAR PHYSICS, Vol: 125, ISSN: 0146-6410
  • Journal article
    Adam A, Figueras P, Jacobson T, Wiseman Tet al., 2022,

    Rotating black holes in Einstein-aether theory

    , CLASSICAL AND QUANTUM GRAVITY, Vol: 39, ISSN: 0264-9381
  • Journal article
    Vasiliauskaite V, Evans TS, Expert P, 2022,

    Cycle analysis of directed acyclic graphs

    , Physica A: Statistical Mechanics and its Applications, Vol: 596, Pages: 1-22, ISSN: 0378-4371

    In this paper, we employ the decomposition of a directed network as an undirected graph plus its associated node meta-data to characterise the cyclic structure found in directed networks by finding a Minimal Cycle Basis of the undirected graph and augmenting its components with direction information. We show that only four classes of directed cycles exist, and that they can be fully distinguished by the organisation and number of source–sink node pairs and their antichain structure. We are particularly interested in Directed Acyclic Graphs and introduce a set of metrics that characterise the Minimal Cycle Basis using the Directed Acyclic Graphs meta-data information. In particular, we numerically show that transitive reduction stabilises the properties of Minimal Cycle Bases measured by the metrics we introduced while retaining key properties of the Directed Acyclic Graph. This makes the metrics a consistent characterisation of Directed Acyclic Graphs and the systems they represent. We measure the characteristics of the Minimal Cycle Bases of four models of transitively reduced Directed Acyclic Graphs and show that the metrics introduced are able to distinguish the models and are sensitive to their generating mechanisms.
  • Journal article
    Duff MJ, 2022,

    The conformal brane-scan: an update

    , JOURNAL OF HIGH ENERGY PHYSICS, Vol: 2022, ISSN: 1029-8479

    Generalizing the The Membrane at the End of the Universe, a 1987 paper Supersingletons by Blencowe and the author conjectured the existence of BPS p-brane configurations (p = 2, 3, 4, 5) and corresponding CFTs on the boundary of anti-de Sitter space with symmetries appearing in Nahm’s classification of superconformal algebras: OSp(N|4) N = 8, 4, 2, 1; SU(2, 2|N) N = 4, 2, 1; F 2(4); OSp(8∗|N), N = 4, 2. This correctly predicted the D3-brane with SU(2, 2|4) on AdS5 × S5 and the M5-brane with OSp(8∗|4) on AdS7 × S4, in addition to the known M2-brane with OSp(8|4) on AdS4 × S7. However, finding non-singular AdS solutions matching the other symmetries was less straightforward. Here we perform a literature search and confirm that all of the empty slots have now been filled, thanks to a number of extra ingredients including warped products and massive Type IIA. Orbifolds, orientifolds and S-folds also play a part providing examples not predicted: SU(2, 2|3), OSp(3|4), OSp(5|4) and OSp(6|4) but not OSp(7|4). We also examine the status of p = (0, 1) configurations.
  • Journal article
    Josse G, Malek E, Petrini M, Waldram Det al., 2022,

    The higher-dimensional origin of five-dimensional N=2 gauged supergravities

    , The Journal of High Energy Physics, Vol: 2022, ISSN: 1029-8479

    Using exceptional generalised geometry, we classify which five-dimensional N = 2 gauged supergravities can arise as a consistent truncation of 10-/11-dimensional supergravity. Exceptional generalised geometry turns the classification into an algebraic problem of finding subgroups GS ⊂ USp(8) ⊂ E6(6) that preserve exactly two spinors. Moreover, the intrinsic torsion of the GS structure must contain only constant singlets under GS, and these, in turn, determine the gauging of the five-dimensional theory. The resulting five-dimensional theories are strongly constrained: their scalar manifolds are necessarily symmetric spaces and only a small number of matter multiplets can be kept, which we completely enumerate. We also determine the largest reductive and compact gaugings that can arise from consistent truncations.
  • Journal article
    Seibold FK, Sfondrini A, 2022,

    Transfer matrices for AdS3/CFT2

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Ashmore A, Petrini M, Tasker EL, Waldram Det al., 2022,

    Exactly marginal deformations and their supergravity duals

    , Physical Review Letters, Vol: 128, Pages: 1-6, ISSN: 0031-9007

    We study the space of supersymmetric AdS5 solutions of type IIB supergravity corresponding to the conformal manifold of the dual N=1 conformal field theory. We show that the background geometry naturally encodes a generalized holomorphic structure, dual to the superpotential of the field theory, with the existence of the full solution following from a continuity argument. In particular, this work allows us to address the long-standing problem of finding the gravity dual of the generic N=1 deformations of N=4 conformal field theory: even if we are not able to give it in a fully explicit form, we provide a proof-of-existence of the supergravity solution. Using this formalism, we derive a new result for the Hilbert series of the deformed field theories.
  • Journal article
    Roberts MM, Wiseman T, 2022,

    Curved-space Dirac description of elastically deformed monolayer graphene is generally incorrect

    , PHYSICAL REVIEW B, Vol: 105, ISSN: 2469-9950
  • Journal article
    AbdusSalam SS, Agocs FJ, Allanach BC, Athron P, Balazs C, Bagnaschi E, Bechtle P, Buchmueller O, Beniwal A, Bhom J, Bloor S, Bringmann T, Buckley A, Butter A, Camargo-Molina JE, Chrzaszcz M, Conrad J, Cornell JM, Danninger M, de Blas J, De Roeck A, Desch K, Dolan M, Dreiner H, Eberhardt O, Ellis J, Ben F, Fedele M, Flaecher H, Fowlie A, Gonzalo TE, Grace P, Hamer M, Handley W, Harz J, Heinemeyer S, Hoof S, Hotinli S, Jackson P, Kahlhoefer F, Kowalska K, Kraemer M, Kvellestad A, Martinez ML, Mahmoudi F, Martinez Santos D, Martinez GD, Mishima S, Olive K, Paul A, Prim MT, Porod W, Raklev A, Renk JJ, Rogan C, Roszkowski L, de Austri RR, Sakurai K, Scaffidi A, Scott P, Sessolo EM, Stefaniak T, Stoecker P, Su W, Trojanowski S, Trotta R, Tsai Y-LS, Van den Abeele J, Valli M, Vincent AC, Weiglein G, White M, Wienemann P, Wu L, Zhang Yet al., 2022,

    Simple and statistically sound recommendations for analysing physical theories

    , Reports on Progress in Physics, Vol: 85, ISSN: 0034-4885

    Physical theories that depend on many parameters or are tested against data from many different experiments pose unique challenges to statistical inference. Many models in particle physics, astrophysics and cosmology fall into one or both of these categories. These issues are often sidestepped with statistically unsound ad hoc methods, involving intersection of parameter intervals estimated by multiple experiments, and random or grid sampling of model parameters. Whilst these methods are easy to apply, they exhibit pathologies even in low-dimensional parameter spaces, and quickly become problematic to use and interpret in higher dimensions. In this article we give clear guidance for going beyond these procedures, suggesting where possible simple methods for performing statistically sound inference, and recommendations of readily-available software tools and standards that can assist in doing so. Our aim is to provide any physicists lacking comprehensive statistical training with recommendations for reaching correct scientific conclusions, with only a modest increase in analysis burden. Our examples can be reproduced with the code publicly available at Zenodo.
  • Working paper
    Auclair P, Bacon D, Baker T, Barreiro T, Bartolo N, Belgacem E, Bellomo N, Ben-Dayan I, Bertacca D, Besancon M, Blanco-Pillado JJ, Blas D, Boileau G, Calcagni G, Caldwell R, Caprini C, Carbone C, Chang C-F, Chen H-Y, Christensen N, Clesse S, Comelli D, Congedo G, Contaldi C, Crisostomi M, Croon D, Cui Y, Cusin G, Cutting D, Dalang C, Luca VD, Pozzo WD, Desjacques V, Dimastrogiovanni E, Dorsch GC, Ezquiaga JM, Fasiello M, Figueroa DG, Flauger R, Franciolini G, Frusciante N, Fumagalli J, Garcia-Bellido J, Gould O, Holz D, Iacconi L, Jain RK, Jenkins AC, Jinno R, Joana C, Karnesis N, Konstandin T, Koyama K, Kozaczuk J, Kuroyanagi S, Laghi D, Lewicki M, Lombriser L, Madge E, Maggiore M, Malhotra A, Mancarella M, Mandic V, Mangiagli A, Matarrese S, Mazumdar A, Mukherjee S, Musco I, Nardini G, No JM, Papanikolaou T, Peloso M, Pieroni M, Pilo L, Raccanelli A, Renaux-Petel S, Renzini AI, Ricciardone A, Riotto A, Romano JD, Rollo R, Pol AR, Morales ER, Sakellariadou M, Saltas ID, Scalisi M, Schmitz K, Schwaller P, Sergijenko O, Servant G, Simakachorn P, Sorbo L, Sousa L, Speri L, Steer DA, Tamanini N, Tasinato G, Torrado J, Unal C, Vennin V, Vernieri D, Vernizzi F, Volonteri M, Wachter JM, Wands D, Witkowski LT, Zumalacárregui M, Annis J, Ares FR, Avelino PP, Avgoustidis A, Barausse E, Bonilla A, Bonvin C, Bosso P, Calabrese M, Çalışkan M, Cembranos JAR, Chala M, Chernoff D, Clough K, Criswell A, Das S, Silva AD, Dayal P, Domcke V, Durrer R, Easther R, Escoffier S, Ferrans S, Fryer C, Gair J, Gordon C, Hendry M, Hindmarsh M, Hooper DC, Kajfasz E, Kopp J, Koushiappas SM, Kumar U, Kunz M, Lagos M, Lilley M, Lizarraga J, Lobo FSN, Maleknejad A, Martins CJAP, Meerburg PD, Meyer R, Mimoso JP, Nesseris S, Nunes N, Oikonomou V, Orlando G, Özsoy O, Pacucci F, Palmese A, Petiteau A, Pinol L, Zwart SP, Pratten G, Prokopec T, Quenby J, Rastgoo S, Roest D, Rummukainen K, Schimd C, Secroun A, Sopuerta CF, Tereno I, Tolley A, Urrestilla J, Vagenas EC, Vis JVD, Weygaert RVD, Wardell B, Weiet al., 2022,

    Cosmology with the Laser Interferometer Space Antenna

    , Publisher: ArXiv

    The Laser Interferometer Space Antenna (LISA) has two scientific objectivesof cosmological focus: to probe the expansion rate of the universe, and tounderstand stochastic gravitational-wave backgrounds and their implications forearly universe and particle physics, from the MeV to the Planck scale. However,the range of potential cosmological applications of gravitational waveobservations extends well beyond these two objectives. This publicationpresents a summary of the state of the art in LISA cosmology, theory andmethods, and identifies new opportunities to use gravitational waveobservations by LISA to probe the universe.
  • Journal article
    Leung JS-Y, Hartley J, Nagy JM, Netterfield CB, Shariff JA, Ade PAR, Amiri M, Benton SJ, Bergman AS, Bihary R, Bock JJ, Bond JR, Bonetti JA, Bryan SA, Chiang HC, Contaldi CR, Dore O, Duivenvoorden AJ, Eriksen HK, Farhang M, Filippini JP, Fraisse AA, Freese K, Galloway M, Gambrel AE, Gandilo NN, Ganga K, Gualtieri R, Gudmundsson JE, Halpern M, Hasselfield M, Hilton G, Holmes W, Hristov VV, Huang Z, Irwin KD, Jones WC, Karakci A, Kuo CL, Kermish ZD, Li S, Mak DSY, Mason P, Megerian K, Moncelsi L, Morford TA, Nolta M, Osherson B, Padilla IL, Racine B, Rahlin AS, Reintsema C, Ruhl JE, Runyan MC, Ruud TM, Shaw EC, Shiu C, Soler JD, Song X, Trangsrud A, Tucker C, Tucker RS, Turner AD, van der List JF, Weber AC, Wehus IK, Wen S, Wiebe D, Young EYet al., 2022,

    A Simulation-based Method for Correcting Mode Coupling in CMB Angular Power Spectra

    , ASTROPHYSICAL JOURNAL, Vol: 928, ISSN: 0004-637X
  • Journal article
    de Rham C, Tolley AJ, Zhang J, 2022,

    Causality constraints on gravitational effective field theories

    , Physical Review Letters, Vol: 128, Pages: 1-6, ISSN: 0031-9007

    We consider the effective field theory of gravity around black holes, and show that the coefficients of the dimension-8 operators are tightly constrained by causality considerations. Those constraints are consistent with—but tighter than—previously derived causality and positivity bounds and imply that the effects of one of the dimension-8 operators by itself cannot be observable while remaining consistent with causality. We then establish in which regime one can expect the generic dimension-8 and lower order operators to be potentially observable while preserving causality, providing a theoretical prior for future observations. We highlight the importance of “infrared causality” and show that the requirement of “asymptotic causality” or net (sub)luminality would fail to properly diagnose violations of causality.
  • Journal article
    Bao J, Hanany A, He YH, Hirst Eet al., 2022,

    Some Open Questions in Quiver Gauge Theory

    , Proyecciones, Vol: 41, Pages: 355-386, ISSN: 0716-0917

    Quivers, gauge theories and singular geometries are of great interest in both mathematics and physics. In this note, we collect a few open questions which have arisen in various recent works at the intersection between gauge theories, representation theory, and algebraic geometry. The questions originate from the study of supersymmetric gauge theories in different dimensions with different supersymmetries. Although these constitute merely the tip of a vast iceberg, we hope this guide can give a hint of possible directions in future research.
  • Journal article
    Borsten L, Marrani A, Pope CN, Stelle Ket al., 2022,

    Introduction to the special issue dedicated to Michael J. Duff FRS on the occasion of his 70th birthday

    , PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 478, ISSN: 1364-5021
  • Journal article
    Collaboration SPIDER, Ade PAR, Amiri M, Benton SJ, Bergman AS, Bihary R, Bock JJ, Bond JR, Bonetti JA, Bryan SA, Chiang HC, Contaldi CR, Doré O, Duivenvoorden AJ, Eriksen HK, Farhang M, Filippini JP, Fraisse AA, Freese K, Galloway M, Gambrel AE, Gandilo NN, Ganga K, Gualtieri R, Gudmundsson JE, Halpern M, Hartley J, Hasselfield M, Hilton G, Holmes W, Hristov VV, Huang Z, Irwin KD, Jones WC, Karakci A, Kuo CL, Kermish ZD, Leung JS-Y, Li S, Mak DSY, Mason PV, Megerian K, Moncelsi L, Morford TA, Nagy JM, Netterfield CB, Nolta M, O'Brient R, Osherson B, Padilla IL, Racine B, Rahlin AS, Reintsema C, Ruhl JE, Runyan MC, Ruud TM, Shariff JA, Shaw EC, Shiu C, Soler JD, Song X, Trangsrud A, Tucker C, Tucker RS, Turner AD, List JFVD, Weber AC, Wehus IK, Wen S, Wiebe DV, Young EYet al., 2022,

    A constraint on primordial B-modes from the first flight of the spider balloon-borne telescope

    , The Astrophysical Journal: an international review of astronomy and astronomical physics, Vol: 927, Pages: 1-26, ISSN: 0004-637X

    We present the first linear polarization measurements from the 2015long-duration balloon flight of SPIDER, an experiment designed to map thepolarization of the cosmic microwave background (CMB) on degree angular scales.Results from these measurements include maps and angular power spectra fromobservations of 4.8% of the sky at 95 and 150 GHz, along with the results ofinternal consistency tests on these data. While the polarized CMB anisotropyfrom primordial density perturbations is the dominant signal in this region ofsky, Galactic dust emission is also detected with high significance; Galacticsynchrotron emission is found to be negligible in the SPIDER bands. We employtwo independent foreground-removal techniques in order to explore thesensitivity of the cosmological result to the assumptions made by each. Theprimary method uses a dust template derived from Planck data to subtract theGalactic dust signal. A second approach, employing a joint analysis of SPIDERand Planck data in the harmonic domain, assumes a modified-blackbody model forthe spectral energy distribution of the dust with no constraint on its spatialmorphology. Using a likelihood that jointly samples the template amplitude and$r$ parameter space, we derive 95% upper limits on the primordialtensor-to-scalar ratio from Feldman-Cousins and Bayesian constructions, finding$r<0.11$ and $r<0.19$, respectively. Roughly half the uncertainty in $r$derives from noise associated with the template subtraction. New data at 280GHz from SPIDER's second flight will complement the Planck polarization maps,providing powerful measurements of the polarized Galactic dust emission.
  • Journal article
    Chen CY-R, de Rham C, Margalit A, Tolley AJet al., 2022,

    A cautionary case of casual causality

    , The Journal of High Energy Physics, Vol: 25, Pages: 1-40, ISSN: 1029-8479

    We distinguish between the notions of asymptotic causality and infrared causality for gravitational effective field theories, and show that the latter gives constraints consistent with gravitational positivity bounds. We re-explore the scattering of gravitational waves in a spherically symmetric background in the EFT of gravity in D ≥ 5, for which the leading-order correction to Einstein gravity is determined by the Gauss-Bonnet operator. We reproduce the known result that the truncated effective theory exhibits apparent time advances relative to the background geometry for specific polarisations, which naively signal a violation of causality. We show that by properly identifying the regime of validity of the effective theory, the apparent time advance can be shown to be unresolvable. To illustrate this, we identify specific higher-dimension operators in the EFT expansion which become large for potentially resolvable time advances, rendering the EFT expansion invalid. Our results demonstrate how staying within the confines of the EFT, neither infrared nor asymptotic causality are ever violated for Einstein-Gauss-Bonnet gravity, no matter how low the scale, and furthermore its causality can be understood without appealing to a precise UV completion such as string theory.
  • Journal article
    Golat S, Contaldi CR, 2022,

    All-sky analysis of astrochronometric signals induced by gravitational waves

    , Physical Review D, Vol: 105, Pages: 1-15, ISSN: 2470-0010

    We introduce a unified spin-weighted formalism to describe both timing and astrometric perturbations induced on astrophysical point sources by gravitational waves using a complex spin field on the sphere. This allows the use of spin-weighted spherical harmonics to analyze “astrochronometric” observables. This approach simplifies the interpretation and simulation of anisotropies induced in the observables by gravitational waves. It also allows a simplified derivation of angular cross-spectra of the observables and their relationship with generalized Hellings-Downs correlation functions. The spin-weighted formalism also allows an explicit connection between correlation components and the spin of gravitational wave polarizations and any presence of chirality. We also calculate expected signal-to-noise ratios for observables to compare the utility of timing and deflection observables.
  • Journal article
    de Rham C, Garcia-Saenz S, Heisenberg L, Pozsgay Vet al., 2022,

    Cosmology of extended proca-nuevo

    , Journal of Cosmology and Astroparticle Physics, Vol: 2022, Pages: 1-50, ISSN: 1475-7516

    Proca-Nuevo is a non-linear theory of a massive spin-1 field which enjoys a non-linearly realized constraint that distinguishes it among other generalized vector models. We show that the theory may be extended by the addition of operators of the Generalized Proca class without spoiling the primary constraint that is necessary for consistency, allowing to interpolate between Generalized Proca operators and Proca-Nuevo ones. The constraint is maintained on flat spacetime and on any fixed curved background. Upon mixing extended Proca-Nuevo dynamically with gravity, we show that the constraint gets broken in a Planck scale suppressed way. We further prove that the theory may be covariantized in models that allow for consistent and ghost-free cosmological solutions. We study the models in the presence of perfect fluid matter, and show that they describe the correct number of dynamical variables and derive their dispersion relations and stability criteria. We also exhibit, in a specific set-up, explicit hot Big Bang solutions featuring a late-time self-accelerating epoch, and which are such that all the stability and subluminality conditions are satisfied and where gravitational waves behave precisely as in General Relativity.
  • Journal article
    Dowker F, Wilkes H, 2022,

    An argument for strong positivity of the decoherence functional in the path integral approach to the foundations of quantum theory

    , AVS Quantum Science, Vol: 4, Pages: 012601-012601, ISSN: 2639-0213

    We give an argument for strong positivity of the decoherence functional as the correct, physical positivity condition in formulations of quantum theory based fundamentally on the path integral. We extend to infinite systems work by Boës and Navascués that shows that the set of strongly positive quantum systems is maximal among sets of systems that are closed under tensor product composition. We show further that the set of strongly positive quantum systems is the unique set that is maximal among the sets that are closed under tensor product composition.I. INTRODUCTION
  • Working paper
    Skrzypek T, Tseytlin AA, 2022,

    On type 0 string theory in solvable RR backgrounds

    , Publisher: ArXiv

    Motivated by a possibility of solving non-supersymmetric type 0 string theoryin $AdS_5 \times S^5$ background using integrability, we revisit theconstruction of type 0 string spectrum in some solvable examples of backgroundswith RR fluxes that are common to type IIB and type 0B theories. The presenceof RR fluxes requires the use of a Green-Schwarz description for type 0 stringtheory. Like in flat space, the spectrum of type 0 theory can be derived fromthe type II theory spectrum by a $(-1)^F$ orbifolding, i.e. combining theuntwisted sector where GS fermions are periodic with the twisted sector whereGS fermions are antiperiodic (and projecting out all spacetime fermionicstates). This construction of the type 0 spectrum may also be implemented usinga Melvin background that allows to continuously interpolate between the type IIand type 0 theories. As an illustration, we discuss the type 0B spectrum in thepp-wave background which is the Penrose limit of $AdS_5 \times S^5$ with RR5-form flux and also in the pp-wave background which is the Penrose limit of$AdS_3 \times S^3 \times T^4$ supported by mixed RR and NSNS 3-form fluxes. Weshow that increasing the strength of the RR flux increases the value of theeffective normal ordering constant (which determines the mass of the type 0tachyon) and thus effectively decreases the momentum-space domain ofinstability of the ground state. We also comment on the semiclassical sector ofstates of type 0B theory in $AdS_5 \times S^5$.
  • Working paper
    Beccaria M, Giombi S, Tseytlin A, 2022,

    Wilson loop in general representation and RG flow in 1d defect QFT

    The generalized Wilson loop operator interpolating between the supersymmetric and the ordinary Wilson loop in N=4 SYM theory provides an interesting example of renormalization group flow on a line defect: the scalar coupling parameter ζ has a non-trivial beta function and may be viewed as a running coupling constant in a 1d defect QFT. In this paper we continue the study of this operator, generalizing previous results for the beta function and Wilson loop expectation value to the case of an arbitrary representation of the gauge group and beyond the planar limit. Focusing on the scalar ladder limit where the generalized Wilson loop reduces to a purely scalar line operator in a free adjoint theory, and specializing to the case of the rank k symmetric representation of SU(N), we also consider a certain semiclassical limit where k is taken to infinity with the product kζ2 fixed. This limit can be conveniently studied using a 1d defect QFT representation in terms of N commuting bosons. Using this representation, we compute the beta function and the circular loop expectation value in the large k limit, and use it to derive constraints on the structure of the beta function for general representation. We discuss the corresponding 1d RG flow and comment on the consistency of the results with the 1d defect version of the F-theorem.
  • Journal article
    Bento BV, Dowker F, Zalel S, 2022,

    If time had no beginning: growth dynamics for past-infinite causal sets

    , Classical and Quantum Gravity, Vol: 39, ISSN: 0264-9381

    We explore whether the growth dynamics paradigm of causal set theory is compatible with past-infinite causal sets. We modify the classical sequential growth dynamics of Rideout and Sorkin to accommodate growth 'into the past' and discuss what form physical constraints such as causality could take in this new framework. We propose convex-suborders as the 'observables' or 'physical properties' in a theory in which causal sets can be past-infinite and use this proposal to construct a manifestly covariant framework for dynamical models of growth for past-infinite causal sets.
  • Journal article
    Acharya B, Alexandre J, Benes P, Bergmann B, Bertolucci S, Bevan A, Branzas H, Burian P, Campbell M, Cho YM, de Montigny M, De Roeck A, Ellis JR, El Sawy M, Fairbairn M, Felea D, Frank M, Gould O, Hays J, Hirt AM, Ho DL-J, Hung PQ, Janecek J, Kalliokoski M, Korzenev A, Lacarrere DH, Leroy C, Levi G, Lionti A, Maulik A, Margiotta A, Mauri N, Mavromatos NE, Mermod P, Millward L, Mitsou VA, Ostrovskiy I, Ouimet P-P, Papavassiliou J, Parker B, Patrizii L, Pavalas GE, Pinfold JL, Popa LA, Popa V, Pozzato M, Pospisil S, Rajantie A, de Austri RR, Sahnoun Z, Sakellariadou M, Santra A, Sarkar S, Semenoff G, Shaa A, Sirri G, Sliwa K, Soluk R, Spurio M, Staelens M, Suk M, Tenti M, Togo V, Tuszyn'ski JA, Upreti A, Vento V, Vives Oet al., 2022,

    Search for magnetic monopoles produced via the Schwinger mechanism

    , NATURE, Vol: 602, Pages: 63-+, ISSN: 0028-0836

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://www.imperial.ac.uk:80/respub/WEB-INF/jsp/search-t4-html.jsp Request URI: /respub/WEB-INF/jsp/search-t4-html.jsp Query String: id=215&limit=30&resgrpMemberPubs=true&resgrpMemberPubs=true&page=4&respub-action=search.html Current Millis: 1714414575419 Current Time: Mon Apr 29 19:16:15 BST 2024

Note to staff:  Adding new publications to a research group

  1. Log in to Symplectic.
  2. Click on Menu > Create Links
  3. Choose what you want to create links between – in this case ‘Publications’ and ‘Organisational structures’.
  4. Choose the organisational structure (research group) into which you want to link the publications and check the box next to it.
  5. Now check the box of any publication you want to add to that group. You can use the filters to find what you want and select multiple publications if necessary. 
  6. Scroll to the bottom and click the blue ‘Create new link’ button to link them.
  7. The publications will be added to the group, and will be displayed on the group publications feed within 24 hours (it is not immediate).

Any problems, talk to Tim Evans or the Faculty Web Team.