A5038806090- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Galaxies: Formation, Evolution, Phenomena
- Atomic and Subatomic Physics Research
- Advanced Thermodynamics and Statistical Mechanics
- Scientific Research and Discoveries
- Gamma-ray bursts and supernovae
- High-Energy Particle Collisions Research
- Distributed and Parallel Computing Systems
- Black Holes and Theoretical Physics
- Pulsars and Gravitational Waves Research
- Radioactive Decay and Measurement Techniques
- Neutrino Physics Research
- Astro and Planetary Science
- Radiation Detection and Scintillator Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Radiation Therapy and Dosimetry
- Astronomy and Astrophysical Research
- Particle Accelerators and Free-Electron Lasers
- Advanced Frequency and Time Standards
- Photocathodes and Microchannel Plates
- Gas Sensing Nanomaterials and Sensors
University of Oslo
2015-2024
European Organization for Nuclear Research
2022-2023
Stockholm University
2003-2022
AlbaNova
2003-2022
Universität Hamburg
2011-2014
Scuola Internazionale Superiore di Studi Avanzati
2003-2008
Institute for Physics
2008
Istituto Nazionale di Fisica Nucleare
2008
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2007
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2007
A commonly encountered obstacle in indirect searches for galactic dark matter is how to disentangle possible signals from astrophysical backgrounds. Given that such are most likely subdominant, the search pronounced spectral features plays a key role detection experiments; monochromatic gamma-ray lines or similar related internal bremsstrahlung, particular, provide smoking gun signatures. We perform dedicated latter data taken by Fermi space telescope during its first 43 months. To this end,...
All attempts to directly detect particle dark matter (DM) scattering on nuclei suffer from the partial or total loss of sensitivity for DM masses in GeV range below. We derive novel constraints inevitable existence a subdominant, but highly energetic, component generated through collisions with cosmic rays. Subsequent inside conventional detectors, as well neutrino detectors sensitive nuclear recoils, limits DM-nucleon cross section be below 10^{-31} cm^{2} both spin-independent and...
The AMS experiment onboard the International Space Station has recently provided cosmic ray electron and positron data with unprecedented precision in range from 0.5 to 350 GeV. observed rise fraction at energies above 10 GeV remains unexplained, proposed solutions ranging local pulsars TeV-scale dark matter. Here, we make use of this high quality place stringent limits on matter masses below ~300 GeV, annihilating or decaying leptonic final states, essentially independent origin rise. We...
Weakly interacting massive particles (WIMPs) remain a prime candidate for the cosmological dark matter (DM), even in absence of current collider signals that would unambiguously point to new physics below TeV scale. The self-annihilation these astronomical targets may leave observable imprints cosmic rays various kinds. In this review, we focus on gamma which argue play pronounced role among possible messengers. We discuss most promising spectral and spatial signatures look for, give an...
The cold dark matter paradigm describes the large-scale structure of Universe remarkably well. However, there exists some tension with observed abundances and internal density structures both field dwarf galaxies galactic satellites. Here, we demonstrate that a simple class models may offer viable solution to all these problems simultaneously. Their key phenomenological properties are velocity-dependent self-interactions mediated by light vector messenger thermal production much later...
We present the first simulations within an effective theory of structure formation (ETHOS), which includes effect interactions between dark matter and radiation on linear initial power spectrum self-interactions during non-linear formation. simulate a Milky Way-like halo in four different models cold case. Our highest resolution simulation has particle mass $2.8\times 10^4\,{\rm M}_\odot$ softening length $72.4\,{\rm pc}$. demonstrate that all alternative have only negligible impact large...
We formulate an effective theory of structure formation (ETHOS) that enables cosmological to be computed in almost any microphysical model dark matter physics. This framework maps the detailed theories particle interactions into physical parameters shape linear power spectrum and self-interaction transfer cross section non-relativistic matter. These are input simulations, which follow evolution galactic distributions. Models with similar ETHOS but different physics would nevertheless result...
For a Gaussian spectrum of primordial density fluctuations, ultracompact minihalos (UCMHs) dark matter are expected to be produced in much greater abundance than, e.g., black holes. Forming shortly after matter-radiation equality, these objects would develop very dense and spiky profiles. In the standard scenario where consists thermally-produced, weakly-interacting massive particles, UCMHs could thus appear as highly luminous gamma-ray sources, or leave an imprint cosmic microwave...
One of the simplest viable models for dark matter is an additional neutral scalar, stabilised by a Z2 symmetry. Using GAMBIT package and combining results from four independent samplers, we present Bayesian frequentist global fits this model. We vary singlet mass coupling along with 13 nuisance parameters, including nuclear uncertainties relevant direct detection, local density, selected quark masses couplings. include relic density measured Planck, searches LUX, PandaX, SuperCDMS XENON100,...
We provide an updated assessment of the power Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at TeV scale, via associated gamma-ray signal from pair-annihilating particles in region around Galactic centre. find that CTA will open a new window discovery potential, significantly extending range robustly testable models given standard cuspy profile density distribution. Importantly, even cored profile, projected sensitivity be sufficient probe various...
Abstract Gravitational waves from a first-order cosmological phase transition, at temperatures the MeV-scale, would arguably be most exciting explanation of common red spectrum reported by NANOGrav collaboration, not least because this direct evidence physics beyond standard model. Here we perform detailed analysis whether such an interpretation is consistent with constraints on released energy deriving big bang nucleosynthesis and cosmic microwave background. We find that transition in...
Abstract Sub-GeV dark matter (DM) particles produced via thermal freeze-out evade many of the strong constraints on heavier DM candidates but at same time face a multitude new from laboratory experiments, astrophysical observations and cosmological data. In this work we combine all these in order to perform frequentist Bayesian global analyses fermionic scalar sub-GeV coupled photon with kinetic mixing. For DM, find viable parameter regions close resonance, which expand significantly when...
The space-borne antimatter experiment PAMELA has recently reported a surprising rise in the positron to electron ratio at high energies. It also been found that electromagnetic radiative corrections some cases may boost gamma-ray yield from supersymmetric dark matter annihilations galactic halo by up three or four orders of magnitude, providing distinct spectral signatures for indirect searches look for. Here, we investigate whether same type can lead sizeable enhancements yield. We find...
The kinetic decoupling of weakly interacting massive particles (WIMPs) in the early universe sets a scale that can directly be translated into small-scale cutoff spectrum matter density fluctuations. formalism presented here allows precise description process and thus determination this to high accuracy from details underlying WIMP microphysics. With temperatures several MeV few GeV, smallest protohalos formed range between 10-11 almost 10-3 solar masses—a somewhat smaller than what was...
A TeV gamma-ray signal from the direction of Galactic center (GC) has been detected by HESS experiment. Here, we investigate whether Kaluza-Klein (KK) dark matter annihilations near GC can be explanation. Including contributions internal bremsstrahlung as well subsequent decays quarks and tau leptons, find a very flat spectrum which drops abruptly at particle mass. For KK mass about 1 TeV, this gives good fit to data below TeV. similar model, with gauge coupling roughly 3 times large 10...
Weakly interacting massive particles (WIMPs) are arguably the most natural dark matter candidates from a particle physics point of view. After their number density has frozen out in early universe, thereby setting relic today, WIMPs still kept very close to thermal equilibrium by scattering events with standard model particles. The complete decoupling bath happens as late at temperatures around ∼1−10 MeV and provides an important cosmological scale that can directly be translated into small...
We introduce DarkBit, an advanced software code for computing dark matter constraints on various extensions to the Standard Model of particle physics, comprising both new native and interfaces external packages. This release includes a dedicated signal yield calculator gamma-ray observations, which significantly extends current tools by implementing cascade-decay Monte Carlo, as well likelihood future experiments (gamLike). provides general solution studying complex physics models that...
We investigate the sensitivity of Gamma-ray Large Area Space Telescope (GLAST) for indirectly detecting weakly interacting massive particles (WIMPs) through γ-ray signal that their pair annihilation produces. WIMPs are among favorite candidates explaining compelling evidence about 80% mass in Universe is non-baryonic dark matter (DM). They serendipitously motivated by various extensions standard model particle physics such as supersymmetry and universal extra dimensions (UED). With its...
Coupling dark matter to light new particles is an attractive way combine thermal production with strong velocity-dependent self-interactions. Here we point out that in such models the annihilation rate generically enhanced by Sommerfeld effect, and derive resulting constraints from cosmic microwave background other indirect detection probes. For frequently studied case of s-wave annihilation, these exclude entire parameter space where self-interactions are large enough address small-scale...
A bstract We perform global fits to the parameters of Constrained Minimal Super-symmetric Standard Model (CMSSM) and a variant with non-universal Higgs masses (NUHM1). In addition constraints from low-energy precision observables cosmological dark matter density, we take into account LHC exclusions searches in jets plus missing transverse energy signatures about 5 fb −1 integrated luminosity. also include most recent upper bound on branching ratio B s → μμ LHCb. Furthermore, implications for...
We describe the open-source global fitting package GAMBIT: Global And Modular Beyond-the-Standard-Model Inference Tool. GAMBIT combines extensive calculations of observables and likelihoods in particle astroparticle physics with a hierarchical model database, advanced tools for automatically building analyses essentially any model, flexible powerful system interfacing to external codes, suite different statistical methods parameter scanning algorithms, host other utilities designed make...
In this paper the authors point out that a basic assumption made in calculating thermal production of dark matter, namely existence local equilibrium during freeze annihilating matter particles, need not always hold. They then provide two methods for dealing with such situation.
Dark matter in the cosmological concordance model is parametrized by a single number, describing covariantly conserved energy density of nonrelativistic fluid. Here we test this assumption model-independent and conservative way considering possibility that, at any point during evolution, dark may be converted into noninteracting form radiation. This scenario encompasses, but more general than, cases where decays or annihilates these states. We show that observations cosmic microwave...