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Journal articleRajantie A, Dotras VAA, Bento A, et al., 2024,
The pivotal role of EU research diasporas in EU-UK scientific and diplomatic relations
, Science & Diplomacy -
Journal articleFredenhagen S, Lausch F, Mkrtchyan K, 2024,
Interactions of massless fermionic fields in three dimensions
, PHYSICAL REVIEW D, Vol: 110, ISSN: 2470-0010 -
Journal articleHull C, Hutt ML, Lindstrom U, 2024,
Gauge-invariant magnetic charges in linearised gravity
, CLASSICAL AND QUANTUM GRAVITY, Vol: 41, ISSN: 0264-9381 -
Journal articleShaw EC, Ade PAR, Akers S, et al., 2024,
In-flight performance of Spider’s 280-GHz receivers
, Journal of Astronomical Telescopes, Instruments, and Systems, Vol: 10, ISSN: 2329-4221Spider is a balloon-borne instrument designed to map the cosmic microwave background at degree-angular scales in the presence of Galactic foregrounds. Spider has mapped a large sky area in the Southern Hemisphere using more than 2000 transition-edge sensors (TESs) during two NASA Long Duration Balloon flights above the Antarctic continent. During its first flight in January 2015, Spider was observed in the 95- and 150-GHz frequency bands, setting constraints on the B-mode signature of primordial gravitational waves. Its second flight in the 2022–2023 season added new receivers at 280 GHz, each using an array of TESs coupled to the sky through feedhorns formed from stacks of silicon wafers. These receivers are optimized to produce deep maps of polarized Galactic dust emission over a large sky area, providing a unique data set with lasting value to the field. We describe the instrument’s performance during Spider’s second flight, focusing on the performance of the 280-GHz receivers. We include details on the flight, in-band optical loading at float, and an early analysis of detector noise.
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Journal articleBenetti Genolini P, Gauntlett JP, Jiao Y, et al., 2024,
Localization of the free energy in supergravity
, Physical Review Letters, Vol: 133, ISSN: 0031-9007We derive a general formula for the gravitational free energy of Euclidean supersymmetric solutions toD ¼ 4, N ¼ 2 gauged supergravity coupled to vector multiplet matter. This allows one to compute the freeenergy without solving any supergravity equations, just assuming the solutions exist. As well as recoveringsome known results in the literature with ease, we also present new supergravity results that match withholographically dual field theory computations.
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Journal articleViegas E, Evans T, 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: 2399-8083Researchers 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.
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Journal articleArav I, Gauntlett JP, Jiao Y, et al., 2024,
Superconformal monodromy defects in N=4 SYM andLS theory
, The Journal of High Energy Physics, Vol: 2024, ISSN: 1029-8479We 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.
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Journal articleAcharya B, Alexandre J, Behera SC, et al., 2024,
MoEDAL search in the CMS beam pipe for magnetic monopoles produced via the Schwinger effect
, Physical Review Letters, Vol: 133, ISSN: 0031-9007We report on a search for magnetic monopoles (MMs) produced in ultraperipheral Pb-Pb collisions during Run 1 of the LHC. The beam pipe surrounding the interaction region of the CMS experiment was exposed to 184.07 μb−1 of Pb-Pb collisions at 2.76 TeV center-of-mass energy per collision in December 2011, before being removed in 2013. It was scanned by the MoEDAL experiment using a SQUID magnetometer to search for trapped MMs. No MM signal was observed. The two distinctive features of this search are the use of a trapping volume very close to the collision point and ultrahigh magnetic fields generated during the heavy-ion run that could produce MMs via the Schwinger effect. These two advantages allowed setting the first reliable, world-leading mass limits on MMs with high magnetic charge.
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Journal articleSeibold FK, Tseytlin AA, 2024,
Scattering on the supermembrane
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleBason D, Di Pietro L, Valandro R, et al., 2024,
BCFT One-point Functions of Coulomb Branch Operators
, Journal of High Energy Physics, Vol: 2024We show that supersymmetry can be used to compute the BCFT one-point function coefficients for chiral primary operators, in 4d N = 2 SCFTs with 12-BPS boundary conditions. The main ingredient is the hemisphere partition function, with the boundary condition on the equatorial S<sup>3</sup>. A supersymmetric Ward identity relates derivatives with respect to the chiral coupling constants to the insertion of the primaries at the pole of the hemisphere. Exact results for the one-point functions can be then obtained in terms of the localization matrix model. We discuss in detail the example of the super Maxwell theory in the bulk, interacting with 3d N = 2 SCFTs on the boundary. In particular we derive the action of the SL(2,ℤ) duality on the one-point functions.
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Journal articleGill AS, Benton SJ, Damaren CJ, et al., 2024,
SuperBIT Superpressure Flight Instrument Overview and Performance: Near-diffraction-limited Astronomical Imaging from the Stratosphere
, ASTRONOMICAL JOURNAL, Vol: 168, ISSN: 0004-6256- Cite
- Citations: 2
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Journal articleEtkin A, Magueijo J, Rassouli F-S, 2024,
Vortices, topology and time
, Physics Letters B: Nuclear Physics and Particle Physics, Vol: 855, ISSN: 0370-2693We 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.
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Journal articleJiang 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 articleGkountoumis 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 articleHull C, Hutt ML, Lindstrom U, 2024,
Charges and topology in linearised gravity
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleChester SM, Dempsey R, Pufu SS, 2024,
Level repulsion in N=4 super-Yang-Mills via integrability, holography, and the bootstrap
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleChen S, Dechant P-P, He Y-H, et al., 2024,
Machine Learning Clifford Invariants of ADE Coxeter Elements
, Advances in Applied Clifford Algebras, Vol: 34, ISSN: 0188-7009<jats:title>Abstract</jats:title><jats:p>There has been recent interest in novel Clifford geometric invariants of linear transformations. This motivates the investigation of such invariants for a certain type of geometric transformation of interest in the context of root systems, reflection groups, Lie groups and Lie algebras: the Coxeter transformations. We perform exhaustive calculations of all Coxeter transformations for<jats:inline-formula><jats:alternatives><jats:tex-math>$$A_8$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>A</mml:mi><mml:mn>8</mml:mn></mml:msub></mml:math></jats:alternatives></jats:inline-formula>,<jats:inline-formula><jats:alternatives><jats:tex-math>$$D_8$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>D</mml:mi><mml:mn>8</mml:mn></mml:msub></mml:math></jats:alternatives></jats:inline-formula>and<jats:inline-formula><jats:alternatives><jats:tex-math>$$E_8$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>E</mml:mi><mml:mn>8</mml:mn></mml:msub></mml:math></jats:alternatives></jats:inline-formula>for a choice of basis of simple roots and compute their invariants, using high-performance computing. This computational algebra paradigm generates a dataset that can then be mined using techniques from data science such as supervised and unsupervised machine learning. In this paper we focus on neural network classification and principal component analysis. Since the output—the invariants—is fully determined by the choice of simple roots and the permutation order of the corresponding reflections in the Coxeter elemen
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Journal articleGonzalez MC, de Rham C, Jaitly S, et al., 2024,
Positivity-causality competition: a road to ultimate EFT consistency constraints
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleMagueijo J, 2024,
Dark matter and spacetime symmetry restoration
, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 109, ISSN: 1550-2368We 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.
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Journal articleGerhardinger M, Giblin Jr JT, Tolley AJ, et al., 2024,
Simulating a numerical UV completion of quartic Galileons
, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 109, ISSN: 1550-7998The 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.
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Journal articleLiu 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 articleChester SM, Pufu SS, Wang Y, et al., 2024,
Bootstrapping M-theory orbifolds
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleBasile T, Joung E, Mkrtchyan K, et 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 articleGautason FF, van Muiden J, 2024,
One-loop quantization of Euclidean D3-branes in holographic backgrounds
, Journal of High Energy Physics, Vol: 2024In 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.
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Journal articleAbend S, Allard B, Alonso I, et al., 2024,
Terrestrial very-long-baseline atom interferometry: workshop summary
, AVS Quantum Science, Vol: 6, ISSN: 2639-0213This 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.
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Journal articleMentasti 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: 1475-7516We 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.
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Journal articleShi D, Shang F, Chen B, et al., 2024,
Local dominance unveils clusters in networks
, Communications Physics, Vol: 7, ISSN: 2399-3650Clusters 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.
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Journal articleHanany A, Kumaran G, Li C, et al., 2024,
Actions on the quiver: discrete quotients on the Coulomb branch
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleAlday LF, Chester SM, Hansen T, et al., 2024,
The AdS Veneziano amplitude at small curvature
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479 -
Journal articleHull CM, 2024,
Magnetic charges for the graviton
, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
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