Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleAlvey J, Contaldi CR, Pieroni M, 2026,
Simulation-based inference with deep ensembles: evaluating calibration uncertainty and detecting model misspecification
, Machine Learning: Science and Technology, Vol: 7, Pages: 015008-015008<jats:title>Abstract</jats:title> <jats:p>Simulation-based inference (SBI) offers a principled and flexible framework for conducting Bayesian inference in any situation where forward simulations are feasible. However, validating the accuracy and reliability of the inferred posteriors remains a persistent challenge. In this work, we point out a simple diagnostic approach rooted in ensemble learning methods to assess the internal consistency of SBI outputs that does not require access to the true posterior. By training multiple neural estimators under identical conditions and evaluating their pairwise Kullback–Leibler (KL) divergences, we define a consistency criterion that quantifies agreement across the ensemble. We highlight two core use cases for this framework: (a) for generating a robust estimate of the systematic uncertainty in parameter reconstruction associated with the training procedure, and (b) for detecting possible model misspecification when using trained estimators on real data. We also demonstrate the relationship between significant KL divergences and issues such as insufficient convergence due to, e.g. too low a simulation budget, or intrinsic variance in the training process. Overall, this ensemble-based diagnostic framework provides a lightweight, scalable, and model-agnostic tool for enhancing the trustworthiness of SBI in scientific applications.</jats:p>
-
Journal articleHull C, Lindström U, Velásquez Cotini Hutt ML, 2026,
Gravitational currents and charges from conformal Killing–Yano tensors
, Classical and Quantum Gravity, Vol: 43, Pages: 025005-025005, ISSN: 0264-9381<jats:title>Abstract</jats:title> <jats:p>We construct a set of higher-form conserved currents on spacetimes admitting conformal Killing–Yano tensors. We find relations between these currents that allow the charge given by integrating one of these currents over a region to be re-expressed as an integral of a covariant quantity over the boundary. In many cases, only a non-covariant form of the boundary integral was previously known. For a special class of these currents the conservation does not rely on field equations, so they give conserved topological charges in any gravitational theory. We discuss the relation of our currents to the Komar current and derive several new properties of conformal Killing–Yano tensors. We study a number of applications of our construction to charges of black hole solutions of Einstein–Maxwell theory, and D-brane solutions of type II supergravity.</jats:p>
-
Journal articleHull C, Zabzine M, 2026,
The symplectic geometry of p-form gauge fields
, Journal of High Energy Physics, Vol: 2026<jats:title> A <jats:sc>bstract</jats:sc> </jats:title> <jats:p>We formulate interacting antisymmetric tensor gauge theory in a configuration space consisting of a pair of dual field strengths which has a natural symplectic structure. The field equations are formulated as the intersection of a pair of submanifolds of this infinite-dimensional symplectic configuration space, one of which is a Lagrangian submanifold while the other is either a coisotropic or Lagrangian submanifold, depending on the topology. Chern-Simons interactions give the configuration space an interesting global structure. We consider in detail the example of a six-dimensional theory of a 3-form field strength coupled to Yang-Mills theory via a Chern-Simons interaction. Our approach applies to a broad class of gauge systems.</jats:p>
-
Journal articleHull C, Lambert N, 2026,
The CFT of Sen’s formulation of chiral gauge fields
, Journal of High Energy Physics, Vol: 2026Sen’s action for chiral bosons in 2 dimensions describes two chiral scalars, one of which couples to the physical metric and one of which couples to a flat metric. It has a generalisation in which the flat metric is replaced by an arbitrary second metric and so can be formulated on any curved world-sheet. When the two metrics are equal, the theory reduces to a βγ system, giving a non-unitary c = 2 conformal field theory. We argue that the relation between this and the theory of two chiral bosonic scalars of the same chirality can be viewed as a ‘bosonisation’. We show that the standard vertex operators for the chiral scalars are vertex operators and line operators in the Sen formulation and derive the formulation in the Sen theory of correlation functions in the chiral scalar theory. The flat space Sen theory can be coupled to two different world-sheet metrics in such a way that one scalar couples to one metric and the other to the other metric, so obtaining the general formulation with two metrics. In d = 4k + 2 dimensions, the bi-metric action for a 2k-form gauge field with self-dual field strength reduces, when the two metrics are equal, to a conformal field theory with a BF-type action, except that B is a self-dual d/2-form and F is a d/2-form field strength, F = dP. The self-duality of B means that this is not a topological theory but instead represents two self-dual gauge fields. This has a generalisation to a democratic action for p-form gauge fields in any dimension.
-
Journal articlede Rham C, Tolley AJ, Wang ZH, et al., 2026,
Primal S-matrix bootstrap with dispersion relations
, Journal of High Energy Physics, Vol: 2026We propose a new method for constructing the consistent space of scattering amplitudes by parameterizing the imaginary parts of partial waves and utilizing dispersion relations, crossing symmetry, and full unitarity. Using this framework, we explicitly compute bounds on the leading couplings and examine the Regge behaviors of the constructed amplitudes. The method also readily accommodates spinning bound states, which we use to constrain glueball couplings. By incorporating dispersion relations, our approach inherently satisfies the Froissart-Martin/Jin-Martin bounds or softer high-energy behaviors by construction. This, in turn, allows us to formulate a new class of fractionally subtracted dispersion relations, through which we investigate the sensitivity of coupling bounds to the asymptotic growth rate.
-
Journal articleBennett S, Hanany A, Kumaran G, 2025,
Orthosymplectic quotient quiver subtraction. Part II. Framed quivers
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleLiu X, Reall HS, Santos JE, et al., 2025,
Ill-posedness of the Cauchy problem for linearized gravity in a cavity with conformal boundary conditions
, CLASSICAL AND QUANTUM GRAVITY, Vol: 42, ISSN: 0264-9381 -
Journal articleIsichei R, Magueijo J, 2025,
Thermodynamics in spacetimes without horizons
, Physical Review D, Vol: 112, ISSN: 2470-0010We consider the energetics and thermodynamics of spacetimes with no horizons, but endowed with a preferred timelike junction surface. They could arise as a limiting case of the gravastar and other constructions regularizing the interior of the horizon of a black hole, or from the conceptual cutting of a portion of a nonasymptotically flat space and gluing it with flat space. We find that such surfaces can be made to have zero energy, so that the energetics of such spaces is not encumbered by them. They do have a transverse pressure, fixed by the jump in surface gravity. A peculiar matter thermodynamics then follows, with well-defined entropy, temperature, and surface pressure, constrained by specific relations arising from the zero energy condition. This is confirmed by the Euclidean path integral, with the proviso that the Tolman-Ehrenfest temperature should be used. The entropy of the space is then the area of the timelike surface in units of a fundamental area, and the matter temperature is proportional to the transverse pressure and so the jump in surface gravity. However, when the gravitational action is added, the free energy of the surface is also zero. The fact that for some such spaces the temperature comes out negative raises interesting questions regarding the third “law” of thermodynamics.
-
Journal articleDowker F, Liu R, Lloyd-Jones D, 2025,
Timelike boundary and corner terms in the causal set action
, CLASSICAL AND QUANTUM GRAVITY, Vol: 42, ISSN: 0264-9381 -
Journal articlede Rham C, Jazayeri S, Tolley AJ, 2025,
Bispectrum islands: Bootstrap bounds on cosmological correlators
, PHYSICAL REVIEW D, Vol: 112, ISSN: 2470-0010 -
Journal articleChester SM, Mouland R, van Muiden J, 2025,
Extremal couplings, graviton exchange, and gluon scattering in AdS
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleGkountoumis G, Hull C, Nian G-E, et al., 2025,
Duality and infinite distance limits in asymmetric freely acting orbifolds
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleDowker F, 2025,
Unifying gravity and quantum theory requires better understanding of time
, NATURE, Vol: 645, Pages: 32-34, ISSN: 0028-0836 -
Journal articleHull CM, 2025,
Monopoles, Dirac strings and generalised symmetries
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleTseytlin AA, Wang Z, 2025,
On world-sheet S-matrix of NSR string in static gauge
, NUCLEAR PHYSICS B, Vol: 1018, ISSN: 0550-3213 -
Journal articleBeccaria M, Roiban R, Tseytlin AA, 2025,
2-loop scattering on superstring and supermembrane in flat space
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleBorsten L, Duff MJ, Kanakaris D, et al., 2025,
Duality anomalies in linearized gravity
, PHYSICAL REVIEW D, Vol: 112, ISSN: 2470-0010- Cite
- Citations: 1
-
Journal articleChester SM, Ferrero P, Pavarini DR, 2025,
Modular invariant gluon-graviton scattering in AdS at one loop
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleElder B, Mentasti G, Pasatembou E, et al., 2025,
Prospects for detecting new dark physics with the next generation of atomic clocks
, Physical Review D, Vol: 112, ISSN: 2470-0010Wide classes of new fundamental physics theories cause apparent variations in particle mass ratios in space and time. In theories that violate the weak equivalence principle (EP), those variations are not uniform across all particles and may be detected with atomic and molecular clock frequency comparisons. In this work we explore the potential to detect those variations with near-future clock comparisons. We begin by searching published clock data for variations in the electron-proton mass ratio. We then undertake a statistical analysis to model the noise in a variety of clock pairs that can be built in the near future according to the current state of the art, determining their sensitivity to various fundamental physics signals. Those signals are then connected to constraints on fundamental physics theories that lead directly or indirectly to an effective EP-violating, including those motivated by dark matter, dark energy, the vacuum energy problem, unification or other open questions of fundamental physics. This work results in projections for tight new bounds on fundamental physics that could be achieved with atomic and molecular clocks within the next few years. Our code for this work is packaged into a forecast tool that translates clock characteristics into bounds on fundamental physics.
-
Journal articleGenolini PB, Gauntlett JP, Jiao Y, et al., 2025,
Equivariant localization for D = 4 gauged supergravity
, The Journal of High Energy Physics, Vol: 2025, Pages: 0-78, ISSN: 1029-8479We consider supersymmetric solutions of D = 4, N = 2 Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Such solutions admit an R-symmetry Killing vector, ξ, constructed as a bilinear in the Killing spinor. The Killing spinor bilinears can also be used to construct polyforms that are equivariantly closed under the action of the equivariant exterior derivative d<inf>ξ</inf> = d – ξ⌟. This allows one to compute various flux integrals and the on-shell action using localization, without solving any supergravity equations, just assuming the supersymmetric solutions exist. The flux integrals allow one to obtain important UV-IR relations, relating fixed point data in the bulk to data on the asymptotic AdS boundary, allowing one to express the gravitational free energy in terms of boundary SCFT data. We illustrate the formalism with a number of examples, including classes of solutions which are unlikely to be ever constructed in closed form.
-
Journal articleAbitbol M, Abril-Cabezas I, Adachi S, et al., 2025,
The Simons Observatory: science goals and forecasts for the enhanced Large Aperture Telescope
, Journal of Cosmology and Astroparticle Physics, Vol: 2025, ISSN: 1475-7516We describe updated scientific goals for the wide-field, millimeter-wave survey that will be produced by the Simons Observatory (SO). Significant upgrades to the 6-meter SO Large Aperture Telescope (LAT) are expected to be complete by 2028, and will include a doubled mapping speed with 30,000 new detectors and an automated data reduction pipeline. In addition, a new photovoltaic array will supply most of the observatory's power. The LAT survey will cover about 60% of the sky at a regular observing cadence, with five times the angular resolution and ten times the map depth of the Planck satellite. The science goals are to: (1) determine the physical conditions in the early universe and constrain the existence of new light particles; (2) measure the integrated distribution of mass, electron pressure, and electron momentum in the late-time universe, and, in combination with optical surveys, determine the neutrino mass and the effects of dark energy via tomographic measurements of the growth of structure at redshifts z ≲ 3; (3) measure the distribution of electron density and pressure around galaxy groups and clusters, and calibrate the effects of energy input from galaxy formation on the surrounding environment; (4) produce a sample of more than 30,000 galaxy clusters, and more than 100,000 extragalactic millimeter sources, including regularly sampled AGN light-curves, to study these sources and their emission physics; (5) measure the polarized emission from magnetically aligned dust grains in our Galaxy, to study the properties of dust and the role of magnetic fields in star formation; (6) constrain asteroid regoliths, search for Trans-Neptunian Objects, and either detect or eliminate large portions of the phase space in the search for Planet 9; and (7) provide a powerful new window into the transient universe on time scales of minutes to years, concurrent with observations from the Vera C. Rubin Observatory of overlapping sky.
-
Journal articleIsichei R, Magueijo J, 2025,
Attractive voids
, INTERNATIONAL JOURNAL OF MODERN PHYSICS D, Vol: 34, ISSN: 0218-2718 -
Journal articleChester SM, Komargodski Z, 2025,
Symmetry enhancement, symmetry-protected topological absorption, and duality in QED3
, PHYSICAL REVIEW B, Vol: 112, ISSN: 2469-9950- Cite
- Citations: 1
-
Journal articleChester SM, Dempsey R, Pufu SS, 2025,
Higher-derivative corrections in M-theory from precision numerical bootstrap
, JOURNAL OF HIGH ENERGY PHYSICS- Cite
- Citations: 1
-
Journal articleBassani P, Magueijo J, Mukohyama S, 2025,
Violations of energy conservation in Horava-Lifshitz gravity: a new ingredient in the dark matter puzzle
, JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, ISSN: 1475-7516 -
Journal articleBennett S, Hanany A, Kumaran G, et al., 2025,
Quiver subtraction on the Higgs branch
, NUCLEAR PHYSICS B, Vol: 1016, ISSN: 0550-3213- Cite
- Citations: 3
-
Journal articleAlbertini E, Platt D, Wiseman T, 2025,
Towards a uniqueness theorem for static black holes in Kaluza-Klein theory with small circle size
, JOURNAL OF HIGH ENERGY PHYSICS- Cite
- Citations: 2
-
Journal articleKozuszek J, Wiseman T, 2025,
Well-posedness of minimal dRGT massive gravity
, JOURNAL OF HIGH ENERGY PHYSICS -
Journal articleChester SM, Su N, 2025,
Upper critical dimension of the 3-state Potts model
, Physical Review D, Vol: 111, ISSN: 2470-0010<jats:p>We consider the 3-state Potts model in <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>d</a:mi><a:mo>≥</a:mo><a:mn>2</a:mn></a:math> dimensions. For <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>d</c:mi></c:math> less than the upper critical dimension <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msub><e:mi>d</e:mi><e:mrow><e:mi>crit</e:mi></e:mrow></e:msub></e:math>, the model has a critical and a tricritical fixed point. In <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mi>d</g:mi><g:mo>=</g:mo><g:mn>2</g:mn></g:math>, these fixed points are described by minimal models, and so are exactly solvable. For <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mi>d</i:mi><i:mo>></i:mo><i:mn>2</i:mn></i:math>, however, strong coupling makes them difficult to study and there is no consensus on the value of <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:msub><k:mi>d</k:mi><k:mrow><k:mi>crit</k:mi></k:mrow></k:msub></k:math>. We use the numerical conformal bootstrap to compute critical exponents of both the critical and tricritical fixed points for general <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:mi>d</m:mi></m:math>. In <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"><o:mi>d</o:mi><o:mo>=</o:mo><o:mn>2</o:mn></o:math> our results ma
-
Journal articleWebb JK, Lee C-C, Milakovic D, et al., 2025,
Correction to: The mystery of alpha and the isotopes
, Monthly Notices of the Royal Astronomical Society, Vol: 540, Pages: L13-L13, ISSN: 0035-8711
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.
Note to staff: Adding new publications to a research group
- Log in to Symplectic.
- Click on Menu > Create Links
- Choose what you want to create links between – in this case ‘Publications’ and ‘Organisational structures’.
- Choose the organisational structure (research group) into which you want to link the publications and check the box next to it.
- 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.
- Scroll to the bottom and click the blue ‘Create new link’ button to link them.
- 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.