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  • Journal article
    Tolley AJ, 2020,

    TT(T)over-bar deformations, massive gravity and non-critical strings

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Ciacci A, Falkenberg M, Manani KA, Evans TS, Peters NS, Christensen Ket al., 2020,

    Understanding the transition from paroxysmal to persistent atrial fibrillation

    , Physical Review Research, Vol: 2, Pages: 1-23, ISSN: 2643-1564

    Atrial fibrillation (AF) is the most common cardiac arrhytmia, characterisedby the chaotic motion of electrical wavefronts in the atria. In clinicalpractice, AF is classified under two primary categories: paroxysmal AF, shortintermittent episodes separated by periods of normal electrical activity, andpersistent AF, longer uninterrupted episodes of chaotic electrical activity.However, the precise reasons why AF in a given patient is paroxysmal orpersistent is poorly understood. Recently, we have introduced the percolationbased Christensen-Manani-Peters (CMP) model of AF which naturally exhibits bothparoxysmal and persistent AF, but precisely how these differences emerge in themodel is unclear. In this paper, we dissect the CMP model to identify the causeof these different AF classifications. Starting from a mean-field model wherewe describe AF as a simple birth-death process, we add layers of complexity tothe model and show that persistent AF arises from the formation of temporallystable structural re-entrant circuits that form from the interaction ofwavefront collisions during paroxysmal AF. These results are compatible withrecent findings suggesting that the formation of re-entrant drivers in fibroticborder zones perpetuates persistent AF.
  • Working paper
    Contaldi CR, 2020,

    COVID-19: nowcasting reproduction factors using biased case testing data

    , Publisher: arXiv

    Timely estimation of the current value for COVID-19 reproduction factor $R$has become a key aim of efforts to inform management strategies. $R$ is animportant metric used by policy-makers in setting mitigation levels and is alsoimportant for accurate modelling of epidemic progression. This brief paperintroduces a method for estimating $R$ from biased case testing data. Usingtesting data, rather than hospitalisation or death data, provides a muchearlier metric along the symptomatic progression scale. This can be hugelyimportant when fighting the exponential nature of an epidemic. We develop apractical estimator and apply it to Scottish case testing data to infer acurrent (20 May 2020) $R$ value of $0.74$ with $95\%$ confidence interval$[0.48 - 0.86]$.
  • Journal article
    Stelle KS, 2020,

    Mass gaps and braneworlds

    , Journal of Physics A: Mathematical and Theoretical, Vol: 53, ISSN: 1751-8113

    Remembering the foundational contributions of Peter Freund to supergravity, and especially to the problems of dimensional compactification, reduction is considered with a non-compact space transverse to the lower dimensional theory. The known problem of a continuum of Kaluza–Klein states is avoided here by the occurrence of a mass gap between a single normalizable zero-eigenvalue transverse wavefunction and the edge of the transverse state continuum. This style of reduction does not yield a formally consistent truncation to the lower dimensional theory, so developing the lower-dimensional effective theory requires integrating out the Kaluza–Klein states lying above the mass gap.
  • Journal article
    Bruce R, dEnterria D, de Roeck A, Drewes M, Farrar GR, Giammanco A, Gould O, Hajer J, Harland-Lang L, Heisig J, Jowett JM, Kabana S, Krintiras GK, Korsmeier M, Lucente M, Milhano G, Mukherjee S, Niedziela J, Okorokov VA, Rajantie A, Schaumann Met al., 2020,

    New physics searches with heavy-ion collisions at the CERN Large Hadron Collider

    , Journal of Physics G: Nuclear and Particle Physics, Vol: 47, Pages: 1-20, ISSN: 0954-3899

    This document summarises proposed searches for new physics accessible in the heavy-ion mode at the CERN Large Hadron Collider (LHC), both through hadronic and ultraperipheral γγ interactions, and that have a competitive or, even, unique discovery potential compared to standard proton–proton collision studies. Illustrative examples include searches for new particles—such as axion-like pseudoscalars, radions, magnetic monopoles, new long-lived particles, dark photons, and sexaquarks as dark matter candidates—as well as new interactions, such as nonlinear or non-commutative QED extensions. We argue that such interesting possibilities constitute a well-justified scientific motivation, complementing standard quark-gluon-plasma physics studies, to continue running with ions at the LHC after the Run-4, i.e. beyond 2030, including light and intermediate-mass ion species, accumulating nucleon–nucleon integrated luminosities in the accessible fb−1 range per month.
  • Journal article
    Grall T, Jazayeri S, Pajer E, 2020,

    Symmetric scalars

    , Journal of Cosmology and Astroparticle Physics, Vol: 2020, Pages: 031-031
  • Journal article
    Domcke V, Garcia-Bellido J, Peloso M, Pieroni M, Ricciardone A, Sorbo L, Tasinato Get al., 2020,

    Measuring the net circular polarization of the stochastic gravitational wave background with interferometers

    , Journal of Cosmology and Astroparticle Physics, Pages: 1-35, ISSN: 1475-7516

    Parity violating interactions in the early Universe can source a stochastic gravitational wave background (SGWB) with a net circular polarization. In this paper, we study possible ways to search for circular polarization of the SGWB with interferometers. Planar detectors are unable to measure the net circular polarization of an isotropic SGWB . We discuss the possibility of using the dipolar anisotropy kinematically induced by the motion of the solar system with respect to the cosmic reference frame to measure the net circular polarization of the SGWB with planar detectors. We apply this approach to LISA, re-assessing previous analyses by means of a more detailed computation and using the most recent instrument specifications, and to the Einstein Telescope (ET), estimating for the first time its sensitivity to circular polarization. We find that both LISA and ET, despite operating at different frequencies, could detect net circular polarization with a signal-to-noise ratio of order one in a SGWB with amplitude h2 ΩGW sime 10−11. We also investigate the case of a network of ground based detectors. We present fully analytical, covariant formulas for the detector overlap functions in the presence of circular polarization. Our formulas do not rely on particular choices of reference frame, and can be applied to interferometers with arbitrary angles among their arms.
  • Journal article
    Osherson B, Filippini JP, Fu J, Gramillano R, Gualtieri R, Shaw EC, Ade PAR, Amiri M, Benton SJ, Bock JJ, Bond JR, Bryan SA, Chiang HC, Contaldi CR, Dore O, Fraisse AA, Gambrel AE, Gandilo NN, Gudmundsson JE, Halpern M, Hartley JW, Hasselfield M, Hilton G, Holmes W, Hristov VV, Irwin KD, Jones WC, Kermish ZD, Mason P, Megerian K, Moncelsi L, Morford TA, Nagy JM, Netterfield CB, Padilla IL, Rahlin AS, Reintsema C, Ruhl JE, Runyan MC, Shariff JA, Soler JD, Trangsrud A, Tucker C, Tucker RS, Turner AD, Weber AC, Wiebe D, Young EYet al., 2020,

    Particle response of antenna-coupled TES arrays: results from SPIDER and the laboratory

    , Journal of Low Temperature Physics, Vol: 199, Pages: 1127-1136, ISSN: 0022-2291

    Future mm-wave and sub-mm space missions will employ large arrays of multiplexed transition-edge-sensor (TES) bolometers. Such instruments must contend with the high flux of cosmic rays beyond our atmosphere that induce ‘glitches’ in bolometer data, which posed a challenge to data analysis from the Planck bolometers. Future instruments will face the additional challenges of shared substrate wafers and multiplexed readout wiring. In this work, we explore the susceptibility of modern TES arrays to the cosmic ray environment of space using two data sets: the 2015 long-duration balloon flight of the SPIDER cosmic microwave background polarimeter, and a laboratory exposure of SPIDER flight hardware to radioactive sources. We find manageable glitch rates and short glitch durations, leading to minimal effect on SPIDER analysis. We constrain energy propagation within the substrate through a study of multi-detector coincidences and give a preliminary look at pulse shapes in laboratory data.
  • Journal article
    Sirks EL, Clark P, Massey RJ, Benton SJ, Brown AM, Damaren CJ, Eifler T, Fraisse AA, Frenk C, Funk M, Galloway MN, Gill A, Hartley JW, Holder B, Huff EM, Jauzac M, Jones WC, Lagattuta D, Leung JSY, Li L, Luu TVT, McCleary J, Nagy JM, Netterfield CB, Redmond S, Rhodes JD, Romualdez LJ, Schmoll J, Shaaban MM, Tam SIet al., 2020,

    Download by parachute: Retrieval of assets from high altitude balloons

    , Journal of Instrumentation, Vol: 15

    We present a publicly-available toolkit of flight-proven hardware and software to retrieve 5 TB of data or small physical samples from a stratospheric balloon platform. Before launch, a capsule is attached to the balloon, and rises with it. Upon remote command, the capsule is released and descends via parachute, continuously transmitting its location. Software to predict the trajectory can be used to select a safe but accessible landing site. We dropped two such capsules from the SUPERBIT telescope, in September 2019. The capsules took ∼37 minutes to descend from ∼30 km altitude. They drifted 32 km and 19 km horizontally, but landed within 300 m and 600 m of their predicted landing sites. We found them easily, and successfully recovered the data. We welcome interest from other balloon teams for whom the technology would be useful.
  • Journal article
    Beccaria M, Jiang H, Tseytlin AA, 2020,

    Boundary correlators in WZW model on AdS2

    , The Journal of High Energy Physics, Vol: 2020, Pages: 1-37, ISSN: 1029-8479

    Boundary correlators of elementary fields in some 2d conformal field theories defined on AdS2 have a particularly simple structure. For example, the correlators of the Liouville scalar happen to be the same as the correlators of the chiral component of the stress tensor on a plane restricted to the real line. Here we show that an analogous relation is true also in the WZW model: boundary correlators of the WZW scalars have the same structure as the correlators of chiral Kac-Moody currents. This is checked at the level of the tree and one-loop Witten diagrams in AdS2. We also compute some tree-level correlators in a generic σ-model defined on AdS2 and show that they simplify only in the WZW case where an extra Kac-Moody symmetry appears. In particular, the terms in 4- point correlators having logarithmic dependence on 1d cross-ratio cancel only at the WZW point. One motivation behind this work is to learn how to compute AdS2 loop corrections in 2d models with derivative interactions related to the study of correlators of operators on Wilson loops in string theory in AdS.
  • Journal article
    Tseytlin AA, 2020,

    Comments on open string with 'massive' boundary term

    , Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol: 476, Pages: 1-9, ISSN: 1364-5021

    We discuss possible definition of open string path integral in the presence of additional boundary couplings corresponding to the presence of masses at the ends of the string. These couplings are not conformally invariant implying that as in a non-critical string case one is to integrate over the one-dimensional metric or reparametrizations of the boundary. We compute the partition function on the disc in the presence of an additional constant gauge field background and comment on the structure of the corresponding scattering amplitudes.
  • Journal article
    Adshead P, Giblin JT, Pieroni M, Weiner ZJet al., 2020,

    Constraining axion inflation with gravitational waves across 29 decades in frequency

    , Physical Review Letters, Vol: 124, Pages: 1-6, ISSN: 0031-9007

    We demonstrate that gravitational waves generated by efficient gauge preheating after axion inflation generically contribute significantly to the effective number of relativistic degrees of freedom Neff. We show that, with existing Planck limits, gravitational waves from preheating already place the strongest constraints on the inflaton’s possible axial coupling to Abelian gauge fields. We demonstrate that gauge preheating can completely reheat the Universe regardless of the inflationary potential. Further, we quantify the variation of the efficiency of gravitational wave production from model to model and show that it is correlated with the tensor-to-scalar ratio. In particular, when combined with constraints on models whose tensor-to-scalar ratios would be detected by next-generation cosmic microwave background experiments, r≳10−3, constraints from Neff will probe or rule out the entire coupling regime for which gauge preheating is efficient.
  • Journal article
    Adshead P, Giblin JT, Pieroni M, Weiner ZJet al., 2020,

    Constraining axion inflation with gravitational waves from preheating

    , Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 101, Pages: 1-23, ISSN: 1550-2368

    We study gravitational wave production from gauge preheating in a variety of inflationary models, detailing its dependence on both the energy scale and the shape of the potential. We show that preheating into Abelian gauge fields generically leads to a large gravitational wave background that contributes significantly to the effective number of relativistic degrees of freedom in the early universe, Neff. We demonstrate that the efficiency of gravitational wave production is correlated with the tensor-to-scalar ratio, r. In particular, we show that efficient gauge preheating in models whose tensor-to-scalar ratio would be detected by next-generation cosmic microwave background experiments (r≳10−3) will be either detected through its contribution to Neff or ruled out. Furthermore, we show that bounds on Neff provide the most sensitive probe of the possible axial coupling of the inflaton to gauge fields regardless of the potential.
  • Journal article
    Dowker F, Imambaccus N, Owens A, Sorkin R, Zalel Set al., 2020,

    A manifestly covariant framework for causal set dynamics

    , Classical and Quantum Gravity, Vol: 37, Pages: 085003-085003, ISSN: 0264-9381

    We propose a manifestly covariant framework for causal set dynamics. The framework is based on a structure, dubbed covtree, which is a partial order on certain sets of finite, unlabeled causal sets. We show that every infinite path in covtree corresponds to at least one infinite, unlabeled causal set. We show that transition probabilities for a classical random walk on covtree induce a classical measure on the -algebra generated by the stem sets.
  • Journal article
    Binder DJ, Chester SM, Pufu SS, 2020,

    Absence of D4R4 in M-theory from ABJM

    , Journal of High Energy Physics, Vol: 2020

    <jats:title>A<jats:sc>bstract</jats:sc> </jats:title> <jats:p>Supersymmetry allows a <jats:italic>D</jats:italic> <jats:sup>4</jats:sup> <jats:italic>R</jats:italic> <jats:sup>4</jats:sup> interaction in M-theory, but such an interaction is inconsistent with string theory dualities and so is known to be absent. We provide a novel proof of the absence of the <jats:italic>D</jats:italic> <jats:sup>4</jats:sup> <jats:italic>R</jats:italic> <jats:sup>4</jats:sup> M-theory interaction by calculating 4-point scattering amplitudes of 11d supergravitons from ABJM theory. This calculation extends a previous calculation performed to the order corresponding to the <jats:italic>R</jats:italic> <jats:sup>4</jats:sup> interaction. The new ingre- dient in this extension is the interpretation of the fourth derivative of the mass deformed <jats:italic>S</jats:italic> <jats:sup>3</jats:sup> partition function of ABJM theory, which can be determined using supersymmetric localization, as a constraint on the Mellin amplitude associated with the stress tensor mul- tiplet 4-point function. As part of this computation, we relate the 4-point function of the superconformal primary of the stress tensor multiplet of any 3d <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \mathcal{N} $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>N</mml:mi> </mml:math> </jats:alternatives> </jats:inline-formula> = 8 SCFT to some of the 4-point functions of its superconformal descendants. We also provide a concise formula f
  • Journal article
    Chester SM, 2020,

    Genus-2 holographic correlator on AdS5 × S5 from localization

    , Journal of High Energy Physics, Vol: 2020, ISSN: 1029-8479

    <jats:title>A<jats:sc>bstract</jats:sc> </jats:title> <jats:p>We consider the four-point function of the stress tensor multiplet superprimary in <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \mathcal{N} $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>N</mml:mi> </mml:math> </jats:alternatives> </jats:inline-formula> = 4 super-Yang-Mills (SYM) with gauge group SU(<jats:italic>N</jats:italic> ) in the large <jats:italic>N</jats:italic> and large ’t Hooft coupling <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \lambda \equiv {g}_{\mathrm{YM}}^2N $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>λ</mml:mi> <mml:mo>≡</mml:mo> <mml:msubsup> <mml:mi>g</mml:mi> <mml:mi>YM</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> <mml:mi>N</mml:mi> </mml:math> </jats:alternatives> </jats:inline-formula> limit, which is holographically dual to the genus expansion of IIB string theory on AdS<jats:sub>5</jats:sub> <jats:italic>× S</jats:italic> <jats:sup>5</jats:sup>. In [1] it was shown that the integral of this correlator is related to derivatives of the mass deformed <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \mathcal{N} $$</jats:tex-math>
  • Journal article
    Ho DL-J, Rajantie A, 2020,

    Classical production of 't Hooft-Polyakov monopoles from magnetic fields

    , Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 101, Pages: 055003-1-055003-6, ISSN: 1550-2368

    We show that in the SU(2) Georgi-Glashow model, ’t Hooft–Polyakov monopoles are produced by a classical instability in magnetic fields above the Ambjørn-Olesen critical field, which coincides approximately with the field at which Schwinger pair production becomes unsuppressed. Below it, monopoles can be produced thermally, and we show that the rate is higher than for pointlike monopoles by calculating the sphaleron energy as a function of the magnetic field. The results can be applied to production of monopoles in heavy-ion collisions or in the early Universe.
  • Journal article
    Chaemjumrus N, Hull CM, 2020,

    Special holonomy manifolds, domain walls, intersecting branes and T-folds

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Markkanen T, Rajantie A, 2020,

    Scalar correlation functions for a double-well potential in de Sitter space

    , Journal of Cosmology and Astroparticle Physics, Vol: 2020, Pages: 1-23, ISSN: 1475-7516

    We use {the spectral representation of }the stochastic Starobinsky-Yokoyama approach to compute correlation functions in de Sitter space for a scalar field with a symmetric or asymmetric double-well potential. The terms in the spectral expansion are determined by the eigenvalues and eigenfunctions of the time-independent Fokker-Planck differential operator, and we solve them numerically. The long-distance asymptotic behaviour is given by the lowest state in the spectrum, but we demonstrate that the magnitude of the coeffients of different terms can be very different, and the correlator can be dominated by different terms at different distances. This can give rise to potentially observable cosmological signatures. In many cases the dominant states in the expansion do not correspond to small fluctuations around a minimum of the potential and are therefore not visible in perturbation theory. We discuss the physical interpretation these states, which can be present even when the potential has only one minimum.
  • Journal article
    Romualdez LJ, Benton SJ, Brown AM, Clark P, Damaren CJ, Eifler T, Fraisse AA, Galloway MN, Gill A, Hartley JW, Holder B, Huff EM, Jauzac M, Jones WC, Lagattuta D, Leung JS-Y, Li L, Luu TVT, Massey RJ, McCleary J, Mullaney J, Nagy JM, Netterfield CB, Redmond S, Rhodes JD, Schmoll J, Shaaban MM, Sirks E, Tam S-Iet al., 2020,

    Robust diffraction-limited near-infrared-to-near-ultraviolet wide-field imaging from stratospheric balloon-borne platforms-Super-pressure Balloon-borne Imaging Telescope performance.

    , Rev Sci Instrum, Vol: 91

    At a fraction of the total cost of an equivalent orbital mission, scientific balloon-borne platforms, operating above 99.7% of the Earth's atmosphere, offer attractive, competitive, and effective observational capabilities-namely, space-like seeing, transmission, and backgrounds-which are well suited for modern astronomy and cosmology. The Super-pressure Balloon-borne Imaging Telescope (SUPERBIT) is a diffraction-limited, wide-field, 0.5 m telescope capable of exploiting these observing conditions in order to provide exquisite imaging throughout the near-infrared to near-ultraviolet. It utilizes a robust active stabilization system that has consistently demonstrated a 48 mas 1σ sky-fixed pointing stability over multiple 1 h observations at float. This is achieved by actively tracking compound pendulations via a three-axis gimballed platform, which provides sky-fixed telescope stability at < 500 mas and corrects for field rotation, while employing high-bandwidth tip/tilt optics to remove residual disturbances across the science imaging focal plane. SUPERBIT's performance during the 2019 commissioning flight benefited from a customized high-fidelity science-capable telescope designed with an exceptional thermo- and opto-mechanical stability as well as a tightly constrained static and dynamic coupling between high-rate sensors and telescope optics. At the currently demonstrated level of flight performance, SUPERBIT capabilities now surpass the science requirements for a wide variety of experiments in cosmology, astrophysics, and stellar dynamics.
  • Journal article
    Hanany A, Kalveks R, 2020,

    Quiver theories and Hilbert series of classical Slodowy intersections

    , NUCLEAR PHYSICS B, Vol: 952, ISSN: 0550-3213
  • Journal article
    Cabrera S, Hanany A, Sperling M, 2020,

    Magnetic quivers, Higgs branches, and 6d N = (1<i>,</i>0) theories - orthogonal and symplectic gauge groups

    , JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
  • Journal article
    Avis G, Jazayeri S, Pajer E, Supeł Jet al., 2020,

    Spatial curvature at the sound horizon

    , Journal of Cosmology and Astroparticle Physics, Vol: 2020, Pages: 034-034
  • Journal article
    Vasiliauskaite V, Evans TS, 2020,

    Making communities show respect for order

    , Applied Network Science, Vol: 5, Pages: 1-24, ISSN: 2364-8228

    In this work we give a community detection algorithm in which the communities both respects the intrinsic order of a directed acyclic graph and also finds similar nodes. We take inspiration from classic similarity measures of bibliometrics, used to assess how similar two publications are, based on their relative citation patterns. We study the algorithm’s performance and antichain properties in artificial models and in real networks, such as citation graphs and food webs. We show how well this partitioning algorithm distinguishes and groups together nodes of the same origin (in a citation network, the origin is a topic or a research field). We make the comparison between our partitioning algorithm and standard hierarchical layering tools as well as community detection methods. We show that our algorithm produces different communities from standard layering algorithms.
  • Journal article
    Agmon NB, Chester SM, Pufu SS, 2020,

    The M-theory archipelago

    , Journal of High Energy Physics, Vol: 2020

    <jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>We combine supersymmetric localization results and the numerical conformal bootstrap technique to study the 3d maximally supersymmetric (<jats:inline-formula><jats:alternatives><jats:tex-math>$$ \mathcal{N} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>N</mml:mi> </mml:math></jats:alternatives></jats:inline-formula> = 8) CFT on <jats:italic>N</jats:italic> coincident M2-branes (the U(<jats:italic>N</jats:italic>)<jats:sub><jats:italic>k</jats:italic></jats:sub> × U(<jats:italic>N</jats:italic>)<jats:sub><jats:italic>−k</jats:italic></jats:sub> ABJM theory at Chern-Simons level <jats:italic>k</jats:italic> = 1). In particular, we perform a mixed correlator bootstrap study of the superconformal primaries of the stress tensor multiplet and of the next possible lowest-dimension half-BPS multiplet that is allowed by 3d <jats:inline-formula><jats:alternatives><jats:tex-math>$$ \mathcal{N} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>N</mml:mi> </mml:math></jats:alternatives></jats:inline-formula> = 8 superconformal symmetry. Of all known 3d <jats:inline-formula><jats:alternatives><jats:tex-math>$$ \mathcal{N} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>N</mml:mi> </mml:math></jats:alternatives></jats:inline-formula> = 8 SCFTs, the <jats:italic>k</jats:italic> = 1 ABJM theory is the only one that contains both types of multiplets i
  • Working paper
    Bourget A, Cabrera S, Grimminger JF, Hanany A, Sperling M, Zajac A, Zhong Zet al., 2020,

    The Higgs mechanism - Hasse diagrams for symplectic singularities

    , Publisher: SPRINGER
  • Journal article
    Alberte L, de Rham C, Momeni A, Rumbutis J, Tolley AJet al., 2020,

    EFT of interacting spin-2 fields

    , The Journal of High Energy Physics, Vol: 2020, Pages: 1-57, ISSN: 1029-8479

    We consider the effective field theory of multiple interacting massive spin-2 fields. We focus on the case where the interactions are chosen so that the cutoff is the highest possible, and highlight two distinct classes of theories. In the first class, the mass eigenstates only interact through potential operators that carry no derivatives in unitary gauge at leading order. In the second class, a specific kinetic mixing between the mass eigenstates is included non-linearly. Performing a decoupling and ADM analysis, we point out the existence of a ghost present at a low scale for the first class of interactions. For the second class of interactions where kinetic mixing is included, we derive the full Λ3-decoupling limit and confirm the absence of any ghosts. Nevertheless both formulations can be used to consistently describe an EFT of interacting massive spin-2 fields which, for a suitable technically natural tuning of the EFT, have the same strong coupling scale Λ3. We identify the generic form of EFT corrections in each case. By using Galileon Duality transformations for the specific case of two massive spin-2 fields with suitable couplings, the decoupling limit theory is shown to be a bi-Galileon.
  • Book chapter
    Dowker F, 2020,

    Being and Becoming on the Road to Quantum Gravity; or, the Birth of a Baby Is Not a Baby

    , Beyond Spacetime: The Foundations of Quantum Gravity, Pages: 133-142

    I claim that both Being and Becoming are incarnated in a cosmological model within the causal set approach to quantum gravity in which spacetime is fundamentally discrete. I argue that, in the model, Being is subjective whereas Becoming is objective.
  • Journal article
    Binder DJ, Chester SM, Pufu SS, 2020,

    AdS4/CFT3 from weak to strong string coupling

    , Journal of High Energy Physics, Vol: 2020, ISSN: 1029-8479

    <jats:title>A<jats:sc>bstract</jats:sc></jats:title><jats:p>We consider the four-point function of operators in the stress tensor multiplet of the U(<jats:italic>N</jats:italic>)<jats:sub><jats:italic>k</jats:italic></jats:sub><jats:italic>×</jats:italic> U(<jats:italic>N</jats:italic>)<jats:sub><jats:italic>−k</jats:italic></jats:sub> ABJM theory, in the limit where <jats:italic>N</jats:italic> is taken to infinity while <jats:italic>N/k</jats:italic><jats:sup>5</jats:sup> is held fixed. In this limit, ABJM theory is holographically dual to type IIA string theory on AdS<jats:sub>4</jats:sub><jats:italic>×</jats:italic> ℂℙ<jats:sup>3</jats:sup> at finite string coupling <jats:italic>g</jats:italic><jats:sub><jats:italic>s</jats:italic></jats:sub><jats:italic>∼</jats:italic> (<jats:italic>N/k</jats:italic><jats:sup>5</jats:sup>)<jats:sup>1<jats:italic>/</jats:italic>4</jats:sup>. While at leading order in 1<jats:italic>/N</jats:italic>, the stress tensor multiplet four-point function can be computed from type IIA supergravity, in this work we focus on the first subleading correction, which comes from tree level Witten diagrams with an <jats:italic>R</jats:italic><jats:sup>4</jats:sup> interaction vertex. Using superconformal Ward identities, bulk locality, and the mass deformed sphere free energy previously computed to all orders in 1<jats:italic>/N</jats:italic> from supersymmetric localization, we determine this <jats:italic>R</jats:italic><jats:sup>4</jats:sup> correction as a function of <jats:italic>N/k</jats:italic><jats:sup>5</jats:sup>. Taking its flat space limit, w
  • Journal article
    Rajantie A, 2019,

    Monopole-antimonopole pair production by magnetic fields

    , Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol: 377, ISSN: 1364-503X

    Quantum electrodynamics predicts that in a strong electric field, electron–positron pairs are produced by the Schwinger process, which can be interpreted as quantum tunnelling through the Coulomb potential barrier. If magnetic monopoles exist, monopole–antimonopole pairs would be similarly produced in strong magnetic fields by the electromagnetic dual of this process. The production rate can be computed using semiclassical techniques without relying on perturbation theory, and therefore it can be done reliably in spite of the monopoles' strong coupling to the electromagnetic field. This article explains this phenomenon and discusses the bounds on monopole masses arising from the strongest magnetic fields in the universe, which are in neutron stars known as magnetars and in heavy ion collision experiments such as lead–lead collisions carried out in November 2018 in the large Hadron collider at CERN. It will also discuss open theoretical questions affecting the calculation.This article is part of a discussion meeting issue ‘Topological avatars of new physics’.

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