Constraining heavy dark matter with cosmic-ray antiprotons

Cosmic-ray observations provide a powerful probe of dark matter annihilation in the Galaxy. In this paper we derive constraints on heavy dark matter from the recent precise AMS-02 antiproton data. We consider all possible annihilation channels into pairs of standard model particles. Furthermore, we interpret our results in the context of minimal dark matter, including higgsino, wino and quintuplet dark matter. We compare the cosmic-ray antiproton limits to limits from $\gamma$-ray observations of dwarf spheroidal galaxies and to limits from $\gamma$-ray and $\gamma$-line observations towards the Galactic center. While the latter limits are highly dependent on the dark matter density distribution and only exclude a thermal wino for cuspy profiles, the cosmic-ray limits are more robust, strongly disfavoring the thermal wino dark matter scenario even for a conservative estimate of systematic uncertainties.Comment: 14 pages + references, 5 figures; v2: HESS limits added in Fig. 2, matches published versio

Probing dark matter annihilation in the Galaxy with antiprotons and gamma rays

A possible hint of dark matter annihilation has been found in Cuoco, Korsmeier and Kr\"amer (2017) from an analysis of recent cosmic-ray antiproton data from AMS-02 and taking into account cosmic-ray propagation uncertainties by fitting at the same time dark matter and propagation parameters. Here, we extend this analysis to a wider class of annihilation channels. We find consistent hints of a dark matter signal with an annihilation cross-section close to the thermal value and with masses in range between 40 and 130 GeV depending on the annihilation channel. Furthermore, we investigate in how far the possible signal is compatible with the Galactic center gamma-ray excess and recent observation of dwarf satellite galaxies by performing a joint global fit including uncertainties in the dark matter density profile. As an example, we interpret our results in the framework of the Higgs portal model.Comment: 12 pages + references, 4 figures, v2: References added, minor changes in presentation, matches journal versio

Effective field theory interpretation of searches for dark matter annihilation in the Sun with the IceCube Neutrino Observatory

We present a model-independent interpretation of searches for dark matter annihilation in the Sun using an effective field theory approach. We identify a set of effective operators contributing to spin-dependent scattering of dark matter with protons in the non-relativistic limit and explore simple new physics models which would give rise to such operators. Using the limits on the spin-dependent scattering cross-section set by the IceCube collaboration in their search for dark matter annihilation in the Sun, we derive limits on effective couplings and corresponding masses of mediating particles. We show that the effective field theory interpretation of the IceCube searches provides constraints on dark matter complementary to those from relic density observations and searches at the LHC. Finally, we discuss the impact of astrophysical uncertainties on our results.Comment: 16 pages, 6 figures; Added references in v

A global fit of the γ\gamma-ray galactic center excess within the scalar singlet Higgs portal model

We analyse the excess in the $\gamma$-ray emission from the center of our galaxy observed by Fermi-LAT in terms of dark matter annihilation within the scalar Higgs portal model. In particular, we include the astrophysical uncertainties from the dark matter distribution and allow for unspecified additional dark matter components. We demonstrate through a detailed numerical fit that the strength and shape of the $\gamma$-ray spectrum can indeed be described by the model in various regions of dark matter masses and couplings. Constraints from invisible Higgs decays, direct dark matter searches, indirect searches in dwarf galaxies and for $\gamma$-ray lines, and constraints from the dark matter relic density reduce the parameter space to dark matter masses near the Higgs resonance. We find two viable regions: one where the Higgs-dark matter coupling is of ${\cal O}(10^{-2})$, and an additional dark matter component beyond the scalar WIMP of our model is preferred, and one region where the Higgs-dark matter coupling may be significantly smaller, but where the scalar WIMP constitutes a significant fraction or even all of dark matter. Both viable regions are hard to probe in future direct detection and collider experiments.Comment: 20 pages + references, 12 figures; v2: minor changes in presentation, references added, improved scan coverage and updated plots in figs. 6, 8, 9, 10 and 12 accordingly, conclusions unchanged, matches journal versio

Regularity and Symmetry Results for Ground State Solutions of Quasilinear Elliptic Equations

This dissertation deals with boundary value problems similar to the p-Laplace and prescribed mean curvature equation with Dirichlet boundary conditions. The equation is structurally more complicated than the p-Laplace equation and it is elliptic, but not uniformly elliptic. The main results are: - Study of the qualitative behaviour of radially symmetric solutions. - Symmetry of mountain pass solutions using Schwarz symmetrization. - A decay estimate for the Hoelder norm of the derivatives

Diagrams

a) Topics and Objectives. This research group investigates the history and theory of thinking with the help of diagrams. Diagrams are conceived as cognitive instruments which exploit spatial relationships paradigmatically in order to represent, analyze, and generate knowledge. We use the term "diagram" in both a narrow and in an extended sense: defined more narrowly, diagrams are schematic figures such as geometric constructions or chemical structural formulae; defined in an extended sense, the term may also refer to texts, charts, mathematical formulae, in short: all types of inscriptions upon a delimited surface which display diagrammatical aspects. The guiding presuppositions of our research are: (1) by means of spatial logics and topological orders, diagrams are preferred forms for representing non-spatial, theoretical relationships. (2) Diagrams do not display simple ›objects,‹ but instead relationships within a conceptual or knowledge field. (3) As a consequence, diagrams not only open up spaces of representation, but also experimental, explorative, and operational spaces, in many cases involving abstract, non-sensory, or ideational contents. Diagrams render theories susceptible to experience in sensory terms. (4) On the whole, the capacity for graphism may be ranged alongside the capacity for language as a universal anthropological trait. Against this horizon, our research project – whose orientation is epistemological and philosophical – pursues two problems. The first involves the basic contours of a general theory of diagrammatics and – starting from the ›cartographic impulse‹ embodied in Plato’s parable of the line and in Ptolemy’s "handbook of geography" – an ›epistemology of the line‹ as a philosophical reconstruction of the implicit and explicit diagrammatical aspects of philosophical texts. The second problem involves the diagram as a cognitive artifact which is examined from historical and systematic perspectives. b) Methods: Philosophical analysis of texts, case studies of individual thinkers and specific types of diagrams. c) Current state of the discussion within the research group: Basic concepts related to diagrammatics have been elaborated, central episodes in the Occidental theory of the diagram identified and analyzed, and central elements of a general theory of diagrammatic cognition developed. Planned for the future is on the one hand deepened work on historical case studies, and on the other the integration of the hitherto developed modules into a consistent, overarching theory.a) Gegenstände und Ziele. Diese Forschergruppe untersucht Geschichte und Theorie des Denkens mit Hilfe von Diagrammen. Diagramme werden als kognitive Instrumente begriffen, die in paradigmatischer Weise Raumrelationen zur Darstellung, Analyse und Produktion von Wissen nutzen. Wir verwenden den Begriff »Diagramm« in einem engen und einem erweiterten Sinne: Diagramme im engeren Sinne sind schematische Figuren wie etwa geometrische Konstruktionen oder chemische Strukturformeln, im erweiterten Sinne weisen aber auch Schriften, Tabellen, mathematische Formeln, kurz: alle Arten von Inskriptionen auf einer begrenzten Fläche, diagrammatische Dimensionen auf. Die leitenden Annahmen unserer Forschung sind: (1) Diagramme stellen mittels räumlicher Logiken und topologischer Ordnungen bevorzugt nicht-räumliche, theoretische Zusammenhänge dar. (2) Sie zeigen dabei nicht einfach ›Gegenstände‹, sondern Relationen innerhalb von Begriffs- und Wissensfeldern. (3) Dadurch eröffnen sie nicht nur einen Darstellungsraum, sondern auch einen Raum des Experimentierens, Explorierens und Operierens mit oftmals abstrakten, unsinnlichen, ideellen Sachverhalten. Diagramme machen Theorien sinnlich erfahrbar. (4) Insgesamt ist die Fähigkeit zum Graphismus eine dem Sprachvermögen durchaus zur Seite zu stellende universelle anthropologische Auszeichnung. Vor diesem Horizont verfolgt unser epistemologisch-philosophisch orientiertes Forschungsprojekt zwei Fragen. Erstens: Grundlinien einer allgemeinen Theorie der Diagrammatik und – ausgehend von einem ›kartographischen Impuls‹ der in Platons Liniengleichnis und in Ptolemaios’ »Handbuch der Geographie« verkörpert ist – eine ›Epistemologie der Linie‹ als philosophische Rekonstruktion der impliziten und expliziten diagrammatischen Dimensionen in philosophischen Texten. Zweitens: Diagramme als kognitive Artefakte in historischer und systematischer Perspektive. b) Methoden. Philosophische Analyse von Texten, Fallstudien zu einzelnen Denkern und Diagrammtypen. c) Diskussionsstand in der Forschergruppe. Grundbegriffe der Diagrammatik wurden erarbeitet, zentrale Episoden abendländischer Theorie des Diagramms identifiziert und analysiert, zentrale Elemente einer allgemeinen Theorie diagrammatischer Kognition entwickelt. Für die Zukunft steht einerseits die vertiefte Arbeit an historischen Fallstudien, andererseits die Integration der bisherigen Bausteine zu einer konsistenten, übergreifenden Theorie an