Dublin Institute for Advanced Studies
We consider a finite-dimensional oscillatory integral which provides a "finite-dimensional model" for analytically continued SU(2)SU(2) Chern-Simons theory on closed 3-manifolds that are described by plumbing trees. This model allows an efficient description of Stokes phenomenon for perturbative expansions in Chern-Simons theory around classical solutions - SL(2,C)SL(2,\mathbb{C}) flat connections. Moreover, the Stokes coefficients can be categorified, i.e. promoted to graded vector spaces, in terms of this finite-dimensional model. At least naively, the categorification gives BPS spectrum of 5d maximally supersymmetric Yang-Mills theory on the 3-manifold times a line with appropriate boundary conditions. We also comment on necessity of taking into account "flat connections at infinity" to capture Stokes phenomenon for certain 3-manifolds.
Scalar fields in 4D are known to have equivalent dual descriptions in terms of form-field gauge potentials, but this is often regarded as an arcane fact. Why use more complicated formulations when simpler scalar descriptions exist and are equivalent? We describe three ways in which scalars that arise as duals can differ from their garden-variety counterparts. Two of these -- the interchange of weak and strong couplings and utility in bringing topological information to the low-energy theory -- are relatively well-known, but to these we add a third: dualities that map derivative interactions to non-derivative interactions seem not to commute with the general power-counting arguments that quantify control over the low-energy approximation within any EFT involving gravity. Since both sides of the duality must agree on their low-energy limit, the non-derivative interactions on the scalar side of the duality turn out to be suppressed relative to what would generically be assumed. They are nonetheless technically natural, as is particularly clear in the dual formulation. We argue that scalar fields arising as duals (such as the universal axion aa from string vacua) that have the commonly assumed JμμaJ^\mu \partial_\mu a interaction with matter also have JμJμJ^\mu J_\mu contact interactions among the respective currents, some of whose implications we explore. We also emphasize the non-trivial role and cosmological implications of non-propagating 3-form gauge potentials and clarify confusing statements recently made in the literature regarding the validity of duality for massive form fields.
Zero indirect gaps in band models are typically viewed as unstable and achievable only through fine-tuning. Recent works, however, have revealed robust semimetallic phases in Hermitian systems where the indirect gap remains pinned at zero over a finite parameter range. Here, we extend this paradigm to non-Hermitian lattice models by studying a one-dimensional diamond-like system with gain and loss. We show that a zero indirect band gap can remain stable against non-Hermitian perturbations and identify the regimes where this robustness persists. Remarkably, we find that the zero indirect gap induces a suppression of the non-Hermitian skin effect distinct from other physical mechanics already discussed in the literature. Our results reveal new connections between indirect gaps, exceptional points and non-Hermitian skin effect, opening avenues for experimental realizations.
The γ\gamma-ray from Giant molecular clouds (GMCs) is regarded as the most ideal tool to perform in-situ measurement of cosmic ray (CR) density and spectra in our Galaxy. We report the first detection of γ\gamma-ray emissions in the very-high-energy (VHE) domain from the five nearby GMCs with a stacking analysis based on a 4.5-year γ\gamma-ray observation with the Large High Altitude Air Shower Observatory (LHAASO) experiment. The spectral energy distributions derived from the GMCs are consistent with the expected γ\gamma-ray flux produced via CR interacting with the ISM in the energy interval 1 - 100  ~\rm TeV. In addition, we investigate the presence of the CR spectral `knee' by introducing a spectral break in the γ\gamma-ray data. While no significant evidence for the CR knee is found, the current KM2A measurements from GMCs strongly favor a proton CR knee located above 0.9 ~\rm PeV, which is consistent with the latest measurement of the CR spectrum by ground-based experiments.
We present the serendipitous radio-continuum discovery of a likely Galactic supernova remnant (SNR) G305.4-2.2. This object displays a remarkable circular symmetry in shape, making it one of the most circular Galactic SNRs known. Nicknamed Teleios due to its symmetry, it was detected in the new Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe (EMU) radio-continuum images with an angular size of 1320"x1260" and PA = 0 deg. While there is a hint of possible Hα\alpha and gamma-ray emission, Teleios is exclusively seen at radio-continuum frequencies. Interestingly, Teleios is not only almost perfectly symmetric, but it also has one of the lowest surface brightnesses discovered among Galactic SNRs and a steep spectral index of α=0.6±0.3\alpha=-0.6\pm 0.3. Our estimates from HI studies and the Sigma-D relation place Teleios as a type Ia SNR at a distance of either ~2.2 kpc of ~7.7 kpc. This indicates two possible scenarios, either a young (under 1000 yr) or an older SNR (over 10000 yr). With a corresponding diameter of 14/48 pc, our evolutionary studies place Teleios at the either early or late Sedov phase, depending on the distance estimate. However, our modelling also predicts X-ray emission, which we do not see in the present generation of eROSITA images. We also explored a type Iax explosion scenario that points to a much closer distance of <1 kpc and Teleios size of only ~3.3 pc, which would be similar to the only known type Iax remnant SN1181. Unfortunately, all examined scenarios have their challenges, and no definitive supernova (SN) origin type can be established at this stage. Teleios's symmetrical shape suggests expansion into a rarefied and isotropic ambient medium. The low radio surface brightness and the lack of pronounced polarisation can be explained by a high level of ambient rotation measure (RM), with the largest RM being observed at centre.
These lectures aim to highlight the remarkable symbiosis that currently exists between the physics of the very small and the physics of the very large, using the unsolved puzzle of the nature of Dark Energy as a vehicle for so doing. The lectures first summarize what we know observationally about the properties of Dark Energy (and the Dark sector more broadly) and then discuss several approaches to explain them. Along the way this involves determining the types of interactions that would on general grounds be expected to be present in the low-energy limit of fundamental theories involving the many hierarchy of scales we see around us. This includes (but is not limited to) a discussion of technical naturalness (and `t Hooft naturalness) as well as the arguments for their use as a criterion for distinguishing amongst candidate theories. Some recent approaches I find promising are briefly summarized at the end.
We present the first catalog of very-high energy and ultra-high energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory (LHAASO). The catalog was compiled using 508 days of data collected by the Water Cherenkov Detector Array (WCDA) from March 2021 to September 2022 and 933 days of data recorded by the Kilometer Squared Array (KM2A) from January 2020 to September 2022. This catalog represents the main result from the most sensitive large coverage gamma-ray survey of the sky above 1 TeV, covering declination from -20^{\circ} to 80^{\circ}. In total, the catalog contains 90 sources with an extended size smaller than 22^\circ and a significance of detection at >5σ> 5\sigma. Based on our source association criteria, 32 new TeV sources are proposed in this study. Among the 90 sources, 43 sources are detected with ultra-high energy (E>100E > 100 TeV) emission at >4σ> 4\sigma significance level. We provide the position, extension, and spectral characteristics of all the sources in this catalog.
The diffuse Galactic gamma-ray emission is a very important tool used to study the propagation and interaction of cosmic rays in the Milky Way. In this work, we report the measurements of the diffuse emission from the Galactic plane, covering Galactic longitudes from 1515^{\circ} to 235235^{\circ} and latitudes from 5-5^{\circ} to +5+5^{\circ}, in an energy range of 1 TeV to 25 TeV, with the Water Cherenkov Detector Array (WCDA) of the Large High Altitude Air Shower Observatory (LHAASO). After masking the sky regions of known sources, the diffuse emission is detected with 24.6σ24.6\sigma and 9.1σ9.1\sigma significance in the inner Galactic plane and outer Galactic plane, respectively. The WCDA spectra in both regions can be well described by a power-law function, with spectral indices of 2.67±0.05stat-2.67\pm0.05_{\rm stat} in the inner region and 2.83±0.19stat-2.83\pm0.19_{\rm stat} in the outer region, respectively. Combined with the Square Kilometer Array (KM2A) measurements at higher energies, a clear softening of the spectrum is found in the inner region, with change of spectral indices by 0.5\sim0.5 at a break energy around 3030 TeV. The fluxes of the diffuse emission are higher by a factor of 1.52.71.5-2.7 than the model prediction assuming local CR spectra and the gas column density, which are consistent with those measured by the KM2A. Along Galactic longitude, the spatial distribution of the diffuse emission shows deviation from that of the gas column density. The spectral shape of the diffuse emission are possibly variation in different longitude region. The WCDA measurements bridge the gap between the low-energy measurements by space detectors and the ultra-high-energy observations by LHAASO-KM2A and other experiments. These results suggest that improved modeling of the wide-band diffuse emission is required.
A covariant and gauge-invariant field theory for massive fractons in three spacetime dimensions is constructed, demonstrating topological mass generation through a Chern-Simons-like term that also functions as an intrinsic source of fractonic matter. The theory maintains two propagating degrees of freedom, including a massive fractonic charge density, and exhibits a smooth transition to its massless counterpart.
The equivalence principle for test gravitational physics strongly constrains dynamics of spacetime, providing a powerful criterion for selecting candidate theories of gravity. However, checking its validity for a particular theory is often a very difficult task. We devise here a simple theoretical criterion for identifying equivalence principle violations in black hole thermodynamics. Employing this criterion, we prove that Lanczos-Lovelock gravity violates the strong equivalence principle, leaving general relativity as the only local, diffeomorphism-invariant theory compatible with it. However, we also show that certain nonlocal expressions for black hole entropy appear to obey the strong equivalence principle.
Recent calculations in both flat and de Sitter spacetimes have highlighted a tension between the decoupling of high-energy physics from low-energy degrees of freedom and the expectation that quantum systems decohere due to interactions with unknown environments. In effective field theory (EFT), integrating out heavy fields should lead to Hamiltonian time evolution, which preserves the purity of low-energy states. This is consistent with the fact that we never observe isolated quantum states spontaneously decohering in the vacuum due to unknown high-energy physics. However, when a heavy scalar of mass MM is traced out, the resulting purity of a light scalar with mass mm typically appears to scale as a power of 1/M1/M (when mMm\ll M), an effect that cannot be captured by a local effective Hamiltonian. We resolve this apparent paradox by showing that the purity depends on the resolution scale of the EFT and how the environment is traced out. We provide a practical method for diagnosing the purity of low-energy states consistent with EFT expectations, and briefly discuss some of the implications these observations have for how ultraviolet divergences can appear in decoherence calculations.
ETH Zurich logoETH ZurichCalifornia Institute of Technology logoCalifornia Institute of TechnologyUniversity of OsloHeidelberg UniversityINFN Sezione di NapoliUniversity of Waterloo logoUniversity of WaterlooUniversity College London logoUniversity College LondonUniversity of Oxford logoUniversity of OxfordUniversity of BonnUniversity of Copenhagen logoUniversity of CopenhagenUniversity of EdinburghCSICNASA Goddard Space Flight Center logoNASA Goddard Space Flight CenterKU Leuven logoKU LeuvenUniversidad de GranadaUniversity of Southampton logoUniversity of SouthamptonUniversidad Autónoma de MadridUniversité Paris-Saclay logoUniversité Paris-SaclayHelsinki Institute of PhysicsRochester Institute of TechnologyUniversity of HelsinkiPerimeter Institute for Theoretical Physics logoPerimeter Institute for Theoretical PhysicsUniversité de GenèveSorbonne Université logoSorbonne UniversitéUniversity of TurkuLeiden University logoLeiden UniversityCEA logoCEAUniversity of GenevaUniversity of PortsmouthUniversitat de BarcelonaConsejo Superior de Investigaciones CientíficasLudwig-Maximilians-Universität MünchenUniversidad Complutense de MadridUniversity of OuluObservatoire de ParisTechnical University of DenmarkDurham University logoDurham UniversityUniversity of Groningen logoUniversity of GroningenInstituto de Astrofísica e Ciências do EspaçoUniversity of JyväskyläJet Propulsion LaboratoryUniversity of LiègeInstituto de Astrofísica de CanariasUniversity of the WitwatersrandUniversity of NottinghamEuropean Space AgencyÉcole Polytechnique Fédérale de LausanneEuropean Southern Observatory logoEuropean Southern ObservatoryRuhr-Universität BochumUniversity of ZürichSISSADublin Institute for Advanced StudiesIstituto Nazionale di AstrofisicaUniversidad de La LagunaUniversidad de CantabriaUniversity of FribourgInstituto de Física de Cantabria (IFCA)Universidad de ValenciaUniversity of Hawai’iINFN, Sezione di MilanoUniversity of the Western CapeMax Planck Institute for AstronomyLaboratoire d’Astrophysique de MarseilleNORDITAInstitut d’Estudis Espacials de CatalunyaNordic Optical TelescopeInstitut d'Astrophysique de ParisUniversidad de SalamancaINFN - Sezione di PadovaSRON Netherlands Institute for Space ResearchInstitute of Space ScienceInstitut d’Astrophysique SpatialeINFN-Sezione di GenovaTechnical University of CartagenaCentre National de la Recherche ScientifiqueINFN Sezione di LecceUniversità degli studi di Milano StataleINFN-Sezione di BolognaInstitut de Física d’Altes EnergiesUniversità di Napoli ParthenopeInstitute of Space SciencesMuseo Storico della Fisica e Centro Studi e Ricerche Enrico FermiLaboratoire Astroparticule et CosmologieSpace Science Data CenterInstitute for Theoretical PhysicsInstitut de Ciències del CosmosBarcelona Institute of Science and TechnologyCentre National d’Études SpatialesAssociated Universities for Research in AstronomyIndonesian Institute of SciencesPort d’Informació CientíficaInstitute of Space Science and TechnologyLaboratoire de Physique de Clermont-FerrandUniversita degli Studi dell'InsubriaUniversit degli Studi di FerraraUniversit degli Studi di GenovaUniversit Claude Bernard Lyon 1Universit del SalentoAix-Marseille Universit",Universit Paris CitMax Planck-Institute for Extraterrestrial PhysicsSapienza Universit di RomaUniversit di PadovaUniversit degli Studi di FirenzeUniversit degli Studi di TorinoUniversit degli Studi di Napoli Federico IIINAF Osservatorio di Astrofisica e Scienza dello Spazio di BolognaUniversit Di BolognaIFPU Institute for fundamental physics of the UniverseINFN Sezione di TriesteUniversit degli Studi di Trieste
Euclid is expected to establish new state-of-the-art constraints on extensions beyond the standard LCDM cosmological model by measuring the positions and shapes of billions of galaxies. Specifically, its goal is to shed light on the nature of dark matter and dark energy. Achieving this requires developing and validating advanced statistical tools and theoretical prediction software capable of testing extensions of the LCDM model. In this work, we describe how the Euclid likelihood pipeline, Cosmology Likelihood for Observables in Euclid (CLOE), has been extended to accommodate alternative cosmological models and to refine the theoretical modelling of Euclid primary probes. In particular, we detail modifications made to CLOE to incorporate the magnification bias term into the spectroscopic two-point correlation function of galaxy clustering. Additionally, we explain the adaptations made to CLOE's implementation of Euclid primary photometric probes to account for massive neutrinos and modified gravity extensions. Finally, we present the validation of these CLOE modifications through dedicated forecasts on synthetic Euclid-like data by sampling the full posterior distribution and comparing with the results of previous literature. In conclusion, we have identified in this work several functionalities with regards to beyond-LCDM modelling that could be further improved within CLOE, and outline potential research directions to enhance pipeline efficiency and flexibility through novel inference and machine learning techniques.
University of Toronto logoUniversity of TorontoUniversity of Amsterdam logoUniversity of AmsterdamCalifornia Institute of Technology logoCalifornia Institute of TechnologyUniversity of Illinois at Urbana-Champaign logoUniversity of Illinois at Urbana-ChampaignUniversity of OsloUniversity of Cambridge logoUniversity of CambridgeUniversity of ZurichUniversity of Southern California logoUniversity of Southern CaliforniaUniversity of Chicago logoUniversity of ChicagoTel Aviv University logoTel Aviv UniversityUniversity College London logoUniversity College LondonUniversity of Oxford logoUniversity of OxfordUniversity of California, Irvine logoUniversity of California, IrvineUniversity of Copenhagen logoUniversity of CopenhagenUniversity of EdinburghUniversity of British Columbia logoUniversity of British ColumbiaUniversity of CreteKavli Institute for the Physics and Mathematics of the UniverseUniversity of Florida logoUniversity of FloridaINFN Sezione di PisaSpace Telescope Science Institute logoSpace Telescope Science InstituteInstitute for Advanced StudyUniversité Paris-Saclay logoUniversité Paris-SaclayHelsinki Institute of PhysicsStockholm University logoStockholm UniversityUniversity of HelsinkiThe University of ManchesterUniversité de GenèveAalto University logoAalto UniversityQueen Mary University of London logoQueen Mary University of LondonUniversity of PortsmouthMax Planck Institute for AstrophysicsUniversity of IcelandUniversity of NaplesUniversiteit LeidenUniversity of SussexDurham University logoDurham UniversityNiels Bohr InstituteUniversity of JyväskyläUniversity of PadovaInstituto de Astrofísica de CanariasUniversity of the WitwatersrandUniversity of NottinghamEuropean Space AgencyUniversity of Cape TownUniversity of LisbonINFN, Sezione di TorinoPontificia Universidad Católica de ChileDublin Institute for Advanced StudiesJodrell Bank Centre for AstrophysicsINFN, Laboratori Nazionali di FrascatiUniversity of the Basque CountryUniversity of Hawai’iINFN, Sezione di MilanoUniversity of KwaZulu-NatalLudwig-Maximilians-UniversitätInstituto de Astrofísica de Andalucía-CSICUniversity of the Western CapeINAF – Istituto di Astrofisica Spaziale e Fisica Cosmica MilanoLaboratoire d’Astrophysique de MarseilleKavli IPMU (WPI), UTIAS, The University of TokyoMax-Planck Institut für extraterrestrische PhysikINAF-Istituto di RadioastronomiaINAF - Osservatorio di Astrofisica e Scienza dello SpazioLebanese UniversityCambridge UniversityUniversité de MarseilleINFN - Sezione di PadovaINAF-IASF MilanoCosmic Dawn CenterINFN-Sezione di BolognaINFN Sezione di RomaINAF-Osservatorio Astronomico di BolognaINFN Sezione di Roma Tor VergataNational Astronomical Observatories of ChinaSISSA - Scuola Internazionale Superiore di Studi AvanzatiUniversité de LausanneCEA Paris-SaclayUniversity of Oslo, Institute of Theoretical AstrophysicsParis SaclayNational Institute for Physics and Nuclear EngineeringExeter UniversityUniversity of Helsinki, Department of PhysicsUniversité Paris-Saclay, CNRSUniversité de Genève, Département d’AstronomieParis Institute of AstrophysicsAPC, UMR 7164, Université Paris Cité, CNRSInstitute for Advanced Study, Einstein DriveUniversité de Paris, CNRS, Astroparticule et Cosmologie, F-75013 Paris, FranceINAF - Istituto di Radioastronomia, Istituto Nazionale di AstrofisicaINAF - Osservatorio di Astrofisica e Scienza dello Spazio, Istituto Nazionale di AstrofisicaINAF - Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Istituto Nazionale di AstrofisicaUniversity of Helsinki, Department of Physics, and Helsinki Institute of PhysicsINFN-Sezione di Roma TreINFN-Sezione di FerraraUniversit de ParisUniversit Claude Bernard Lyon 1INAF Osservatorio Astronomico di CapodimonteUniversit Lyon 1Instituto de Física Teórica, (UAM/CSIC)RWTH Aachen UniversityINAF Osservatorio Astrofisico di ArcetriUniversit degli Studi di MilanoINAF Osservatorio Astronomico di PadovaUniversit de MontpellierINAF Osservatorio di Astrofisica e Scienza dello Spazio di BolognaUniversit Di BolognaUniversit de Grenoble-AlpesINFN Sezione di TriesteINAF ` Osservatorio Astronomico di TriesteINFN Sezione di FirenzeNorwegian University of Science and TechnologyINAF Osservatorio Astronomico di BreraUniversity of Milano Bicocca
The Euclid mission of the European Space Agency will deliver weak gravitational lensing and galaxy clustering surveys that can be used to constrain the standard cosmological model and extensions thereof. We present forecasts from the combination of these surveys on the sensitivity to cosmological parameters including the summed neutrino mass MνM_\nu and the effective number of relativistic species NeffN_{\rm eff} in the standard Λ\LambdaCDM scenario and in a scenario with dynamical dark energy ($w_0 w_a$CDM). We compare the accuracy of different algorithms predicting the nonlinear matter power spectrum for such models. We then validate several pipelines for Fisher matrix and MCMC forecasts, using different theory codes, algorithms for numerical derivatives, and assumptions concerning the non-linear cut-off scale. The Euclid primary probes alone will reach a sensitivity of σ(Mν)=\sigma(M_\nu)=56meV in the Λ\LambdaCDM+MνM_\nu model, whereas the combination with CMB data from Planck is expected to achieve σ(Mν)=\sigma(M_\nu)=23meV and raise the evidence for a non-zero neutrino mass to at least the 2.6σ2.6\sigma level. This can be pushed to a 4σ4\sigma detection if future CMB data from LiteBIRD and CMB Stage-IV are included. In combination with Planck, Euclid will also deliver tight constraints on $\Delta N_{\rm eff}< 0.144(95 (95%CL) in the \LambdaCDM+CDM+M_\nu++N_{\rm eff}model,or model, or \Delta N_{\rm eff}< 0.063whenfutureCMBdataareincluded.Whenfloating when future CMB data are included. When floating (w_0, w_a),wefindthatthesensitivityto, we find that the sensitivity to N_{\rm eff}$ remains stable, while that to MνM_\nu degrades at most by a factor 2. This work illustrates the complementarity between the Euclid spectroscopic and imaging/photometric surveys and between Euclid and CMB constraints. Euclid will have a great potential for measuring the neutrino mass and excluding well-motivated scenarios with additional relativistic particles.
In this work we investigate discrete-time transport in a generic U(1)-symmetric disordered model tuned across an array of different dynamical regimes. We develop an aggregate quantity, a circular statistical moment, which is a simple function of the magnetization profile and which elegantly captures transport properties of the system. From this quantity we extract transport exponents, revealing behaviors across the phase diagram consistent with localized, diffusive, and - most interestingly for a disordered system - superdiffusive regimes. Investigation of this superdiffusive regime reveals the existence of a prethermal "swappy" regime unique to discrete-time systems in which excitations propagate coherently; even in the presence of strong disorder.
The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented gamma-ray survey of the Galactic Center (GC) region, i.e.{\it i.e.}, the Inner Galaxy Survey, at very high energies (\gtrsim 100 GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant gamma-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section σv\langle \sigma v\rangle. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach σv\langle \sigma v\rangle values of 3.7×1026cm3s1\rm 3.7\times10^{-26} cm^3s^{-1} for 1.5 TeV DM mass in the W+WW^+W^- annihilation channel, and 1.2×1026cm3s1\rm 1.2 \times 10^{-26} cm^3s^{-1} for 0.7 TeV DM mass in the τ+τ\tau^+\tau^- annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based γ\gamma-ray observations thus probe σv\langle \sigma v\rangle values expected from thermal-relic annihilating TeV DM particles.
We consider the unitary dynamics of interacting fermions in the lowest Landau level, on spherical and toroidal geometries. The dynamics are driven by the interaction Hamiltonian which, viewed in the basis of single-particle Landau orbitals, contains correlated pair hopping terms in addition to static repulsion. This setting and this type of Hamiltonian has a significant history in numerical studies of fractional quantum Hall (FQH) physics, but the many-body quantum dynamics generated by such correlated hopping has not been explored in detail. We focus on initial states containing all the fermions in one block of orbitals. We characterize in detail how the fermionic liquid spreads out starting from such a state. We identify and explain differences with regular (single-particle) hopping Hamiltonians. Such differences are seen, e.g. in the entanglement dynamics, in that some initial block states are frozen or near-frozen, and in density gradients persisting in long-time equilibrated states. Examining the level spacing statistics, we show that the most common Hamiltonians used in FQH physics are not integrable, and explain that GOE statistics (level statistics corresponding to the Gaussian Orthogonal Ensemble) can appear in many cases despite the lack of time-reversal symmetry.
University of CanterburyUniversity of Amsterdam logoUniversity of AmsterdamUniversity of Cambridge logoUniversity of CambridgeUniversity of VictoriaChinese Academy of Sciences logoChinese Academy of SciencesUniversity of Oxford logoUniversity of OxfordUniversity of Copenhagen logoUniversity of CopenhagenUniversity of EdinburghRutherford Appleton LaboratoryUniversidad de GranadaJohns Hopkins University logoJohns Hopkins UniversityUniversidad Autónoma de MadridThe Pennsylvania State University logoThe Pennsylvania State UniversityUniversity of Southern QueenslandStockholm University logoStockholm UniversityUppsala UniversitySorbonne Université logoSorbonne UniversitéUniversity of HertfordshireUniversity of TurkuLeiden University logoLeiden UniversityUniversity of SheffieldUniversity of Warwick logoUniversity of WarwickUniversity of PortsmouthUniversitat de BarcelonaMoscow Institute of Physics and TechnologyUniversity of SussexObservatoire de ParisUniversity of HullUniversité Côte d’AzurUniversity of Groningen logoUniversity of GroningenUniversity of BathLund UniversityUniversity of LiègeInstituto de Astrofísica de CanariasUniversity of NottinghamUniversidad de AlicanteEuropean Southern Observatory logoEuropean Southern ObservatoryUniversity of Central LancashireDublin Institute for Advanced StudiesUniversidad de ValparaísoInstituto de Astronomía, Universidad Nacional Autónoma de MéxicoUniversidad de La LagunaUniversité de Picardie Jules VerneQueensland University of TechnologyKapteyn Astronomical InstituteObservatoire astronomique de StrasbourgINAF-Istituto di RadioastronomiaInstituto de Astrofísica de AndalucíaInstitut d’Estudis Espacials de CatalunyaUniversidad de OviedoINAF – Osservatorio Astronomico di RomaLeibniz-Institut für Astrophysik Potsdam (AIP)Hamburger SternwarteCerro Tololo Inter-American ObservatoryGemini ObservatoryCentro de Astrobiología (CSIC-INTA)Instituto de Radioastronomía Milimétrica (IRAM)Institut de Ciències del CosmosINAF Osservatorio Astronomico di CapodimonteMax Planck Institut fr AstronomieAix-Marseille Universit",Universit de LyonUniversit di PisaUniversit di PadovaINAF Osservatorio Astrofisico di ArcetriINAF Osservatorio Astronomico di PadovaUniversit degli Studi di Napoli Federico IIINAF Osservatorio di Astrofisica e Scienza dello Spazio di BolognaUniversidad de AlcalINAF Osservatorio Astronomico di Brera
WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366-959\,nm at R5000R\sim5000, or two shorter ranges at R20000R\sim20\,000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for \sim3 million stars and detailed abundances for 1.5\sim1.5 million brighter field and open-cluster stars; (ii) survey 0.4\sim0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey 400\sim400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z&lt;0.5 cluster galaxies; (vi) survey stellar populations and kinematics in 25000\sim25\,000 field galaxies at 0.3z0.70.3\lesssim z \lesssim 0.7; (vii) study the cosmic evolution of accretion and star formation using &gt;1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z&gt;2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.
X-ray observations of kilo-parsec scale jets indicate that a synchrotron origin of the sustained non-thermal emission is likely. This requires distributed acceleration of electrons up to near PeV energies along the jet. The underlying acceleration mechanism is still unclear. Shear acceleration is a promising candidate, as velocity-shear stratification is a natural consequence of the collimated flow of a jet. We study the details of shear acceleration by solving the steady-state Fokker-Planck-type equation and provide a simple general solution for trans-relativistic jets for a range of magnetohydrodynamic turbulent power-law spectra. In general, the accelerated particle population is a power-law spectrum with an exponential-like cut-off, where the power-law index is determined by the turbulence spectrum and the balance of escape and acceleration of particles. Adopting a simple linearly decreasing velocity profile in the boundary of large-scale jets, we find that the multi-wavelength spectral energy distribution of X-ray jets, such as Centaurus A and 3C 273, can be reproduced with electrons that are accelerated up to \sim PeV. In kpc-scale jets, protons may be accelerated up to \sim EeV, supporting the hypothesis that large-scale jets are strong candidates for ultra-high-energy-cosmic-ray sources within the framework of shear acceleration.
The thermodynamics of black holes in various dimensions are described in the presence of a negative cosmological constant which is treated as a thermodynamic variable, interpreted as a pressure in the equation of state. The black hole mass is then identified with the enthalpy, rather than the internal energy, and heat capacities are calculated at constant pressure not at constant volume. The Euclidean action is associated with a bridge equation for the Gibbs free energy and not the Helmholtz free energy. Quantum corrections to the enthalpy and the equation of state of the BTZ black hole are studied.
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