Dark Matter in Astrophysics and Particle Physics

The following sections are included:

• PREFACE

• CONTENTS

Arguments on the investigation of the Dark Matter particles in the galactic halo are addressed. Recent results obtained by the DAMA/LIBRA set-up – exploiting the model independent annual modulation signature for Dark Matter (DM) particles – are shortly summarized. In fact, the DAMA project is an observatory for rare processes and it is operative deep underground at the Gran Sasso National Laboratory of the I.N.F.N. Its main apparatus is at present the DAMA/LIBRA set-up, consisting of ≃ 250 kg highly radiopure NaI(Tl) detectors. Its first results confirm those obtained by the former DAMA/NaI, supporting the evidence for Dark Matter presence in the galactic halo at 8.2 σ C.L.; in addition, the cumulative data satisfy all the many peculiarities of the DM annual modulation signature. Future perspectives are also addressed.

We consider the prospects for probing low-mass dark matter with the Super-Kamiokande experiment. We show that upcoming analyses including fully-contained events with sensitivity to dark matter masses from 5 to 10 GeV can test the dark matter interpretation of the DAMA/LIBRA signal. We consider prospects of this analysis for two light dark matter candidates: neutralinos and WIMPless dark matter.

In these proceedings, we report on the possible signatures of a light scalar WIMP, a dark matter candidate with M_DM ~ few GeV and which is supposed to interact with the Standard Model particles through the Higgs. Its existence may be related to the annual modulation observed by DAMA/LIBRA.

Supersymmetric models with R-parity conservation provide an excellent candidate for Dark Matter, the Lightest Supersymmetric Particle, which will be searched for with the ATLAS detector at the Large Hadron Collider (LHC). Based on recent simulation studies, we present the discovery potential for Supersymmetry (SUSY) with the first few fb^-1 of ATLAS data, as well as studies of the techniques used to reconstruct decays of SUSY particles at the LHC. We further discuss how such measurements can be used to constrain the underlying Supersymmetric model and hence to extract information about the nature of Dark Matter.

Dark matter in the Universe is likely to be made up of some new, hypothetical particle which would be a part of an extension of the Standard Model of particle physics. After a general introduction, in this talk I present in the framework of two popular unified supersymmetric models Bayesian statistics results for neutralino dark matter in the context of direct detection in underground experiments, and in indirect detection modes of relevance to Fermi and Pamela. While prospects for direct detection look excellent, those for Fermi strongly depend on poorly known cuspiness of the galactic halo in the central region of the Milky Way. Positron flux in those models appears to be significantly below the Pamela result, which on the other hand, may be explained in terms of nearby pulsars.

I report on some scenarios where the gravitino is the dark matter and the supersymmetry breaking mediated by a gauge sector.

We review the phenomenology of gravitino dark matter within supergravity framework. Gravitino can be dark matter if it is the lightest supersymmetric particle, which is stable if R-parity is conserved. There are several distinct scenarios depending on what the next to lightest supersymmetric particle (NLSP) is. We discuss the constraints and summarize the phenomenology of neutralino, stau, stop and sneutrino NLSPs.

Will supersymmetry be found at the CERN Large Hadron Collider (LHC)? If it is, which supersymmetric model is chosen by Nature? Will the available data be enough to sort these puzzles out?

Addressing these questions in this work, we show that the next-to-minimal version of the popular supergravity motivated model (NmSuGra) has a good chance to be observed at the LHC. We also demonstrate that regions of the NmSuGra parameter space which the LHC cannot reach will be detectable at upgraded versions of WIMP direct detection experiments, such as super-CDMS.

We discuss the physical implications of the extra space in higher-dimensional unification, and show that a large extra space requires an extremely small fine structure constant (of the order of 10^-42) for the Kaluza-Klein gauge boson, or else a huge violation of equivalence principle in 4-dimensional Einstein gravity. More importantly, the extra space generates the dilaton which represents the volume element of the extra space. We show that the scalar curvature of the extra space generates the dilaton mass, and that the dilaton mass determines the size of the extra space. Moreover, as a massive scalar graviton, the dilaton can be an excellent candidate of dark matter. Assuming that the dilaton is the dark matter, we estimate the lower bound of the scale of the extra space to be of 10^-9 m.

In this note I discuss about the recent attempts, difficulties and prospects of explaining the current acceleration of the universe (attributed to dark energy) and also dark matter using cosmological warped compactifications of higher-dimensional gravity models, including five-dimensional braneworld models.

Nuclear double beta decay, an extremely rare radioactive decay process, is - in one of its variants - one of the most exciting means of research into particle physics beyond the standard model. The large progress in sensitivity of experiments searching for neutrinoless double beta decay in the last two decades - based largely on the use of large amounts of enriched source material in "active source experiments" - has lead to the observation of the occurrence of this process in nature (on a 6.4 sigma level), with the largest half-life ever observed for a nuclear decay process (2.2×10²⁵ y). This has fundamental consequences for particle physics - violation of lepton number, Majorana nature of the neutrino. These results are independent of any information on nuclear matrix elements (NME)*. It further leads to sharp restrictions for SUSY theories, sneutrino mass, right-handed W-boson mass, superheavy neutrino masses, composite-ness, leptoquarks, violation of Lorentz invariance and equivalence principle in the neutrino sector.

The masses of light-neutrinos are found to be degenerate, and to be at least 0.22±0.02eV. This fixes the contribution of neutrinos as hot dark matter to ≥4.7% of the total observed dark matter. The neutrino mass determined might solve also the dark energy puzzle.

We discuss a TeV-scale model, in which neutrino masses and mixings, dark matter, and baryon asymmetry of the Universe can be simultaneously explained without assuming large hierarchy among the mass scales. Imposing the exact Z₂ symmetry, tiny neutrino masses are generated at the three loop level and stability of the dark matter candidate is guaranteed. Moreover the necessary conditions for the electroweak baryogenesis are satisfied via the extended Higgs sector. The model provides a distinctive experimental signature especially in Higgs phenomenology and dark matter physics.

In a dense cloud of massive fermions interacting by exchange of a light scalar field, the effective mass of the fermion can become negligibly small. As the cloud expands, the effective mass and the total energy density eventually increase with decreasing density. In this regime, the pressure-density relation can approximate that required for dark energy. We apply this phenomenon to the expansion of the Universe with a very light scalar field and infer relations between the parameters available and cosmological observations. Majorana neutrinos at a mass that may have been recently determined, and fermions such as the Lightest Supersymmetric Particle (LSP) may both be consistent with current observations of dark energy.

Nature appears non-local and nonlinear on all observable levels resulting in a large variety of complex phenomena in different scientific fields. In this situation the classical Boltzmann-Gibbs extensive thermo-statistics, applicable whenever microscopic interactions and memory are short ranged and the environment is a continuous and differentiable manifold, fails. We are dealing with systems generally subject to spatial or temporal non-local interactions, evolving in a non-Euclidean/multi-fractal space-time, making their behavior nonextensive. An appropriate generalization of the entropy functional yields upon entropy maximization naturally power-law distributions as manifestation of long-range interactions and correlations in the system, controlled by a single and physically interpretable parameter. Moreover, the nonextensive context is per se subject to entropy bifurcation, generating a tandem character of structures, where higher order stationary states of reduced entropy reside besides lower order stationary states of increased entropy. After reviewing the fundamental theoretical concepts of nonextensive statistics, we focus on the significance and present status with particular attention to the problem of dark matter density distributions in relaxed large scale astrophysical structures as well as the dark energy domain, associating dark energy with self-interacting scalar fields, subject to highest degree of correlations, and appearing as natural content within the nonextensive statistical landscape.

Motivated by the recent results from the PAMELA and ATIC, we study the cosmic-ray electron and positron produced by the decay of gravitino dark matter. We calculate the cosmic-ray electron and positron fluxes and discuss implications to the PAMELA and ATIC data. In this paper, we will show that the observed anomalous fluxes by the PAMELA and ATIC can be explained in such a scenario. We will also discuss the synchrotron radiation flux from the Galactic center in such a scenario.

The assumption of isotropic diffusion has led to successful models for CR transport, capable of explaining the locally observed CR spectra, as well as the diffuse Galactic gamma rays up to 1 GeV. These models currently form the basis for many indirect DM searches. Galactic winds with speeds of more than 100 km/s have been observed by ROSAT. Such wind speeds are incompatible with isotropic diffusion.

Here, a transport model for Galactic CRs compatible with the wind velocities observed by ROSAT is presented. In such a model the contribution of antiprotons and positrons from Dark Matter annihilation to the local fluxes of CRs is reduced by a factor of . We compare the model to the INTEGRAL observations of a large bulge/disk ratio, the WMAP haze and the EGRET excess, all of which have been interpreted in the context of Dark Matter annihilation (DMA) and comment on the DMA interpretation of the PAMELA and ATIC/PPB-BETS results.

Recent measurements of cosmic-ray electron and positron fluxes by PAMELA and ATIC experiments may indicate the existence of annihilating dark matter with large annihilation cross section. We discuss its possible relation to other astrophysical/cosmological observations : gamma-rays, neutrinos, and big-bang nucleosynthesis. It is shown that they give stringent constraints on some annihilating dark matter models.

Can we learn about New Physics with astronomical and astro-particle data? Understanding how this is possible is key to unraveling one of the most pressing mysteries at the interface of cosmology and particle physics: the fundamental nature of dark matter. Rapid progress may be within grasp in the context of an approach which combines information from high-energy particle physics with cosmic-ray and traditional astronomical data. I discuss how modifications to the pair annihilation cross section of dark matter with enhanced rates at low relative velocities can lead to a burst of annihilation in the first dark matter halos. I then introduce a novel approach to particle dark matter searches based on the complementarity of astronomical observations across the electromagnetic spectrum, from radio to X-ray and to gamma-ray frequencies.

We discuss the possibilities for the indirect detection of dark matter annihilation with astronomical observations at X-ray and gamma-ray frequencies. In particular, we describe two studies. First, we use recent X-ray observations of local dwarf spheroidal galaxies to constrain the mass and pair annihilation cross section for particle dark matter. Our results indicate that X-ray observations of dwarf galaxies currently constrain dark matter models at the same level or more strongly than gamma-ray observations, although at the expenses of introducing additional assumptions and related uncertainties in the modeling of diffusion and energy loss processes. The limits we find constrain portions of the supersymmetric parameter space, particularly if the effect of dark matter substructures is included. Then, we investigate the possibility for the Fermi Gamma-ray Space Telescope to detect gamma-ray emission from clusters of galaxies, the largest bound dark matter structures. Clusters are expected to emit gamma rays as a result of (1) a population of high-energy primary and re-accelerated secondary cosmic rays fueled by structure formation and merger shocks, active galactic nuclei and supernovae, and (2) particle dark matter annihilation. Using simulated Fermi observations, we study observational handles that might enable us to distinguish the two emission mechanisms, including the gamma-ray spectra, the spatial distribution of the signal and the associated multi-wavelength emissions. Our study indicates that gamma rays from dark matter annihilation with a high particle mass (m_WIMP > 50 GeV) can be distinguished from a cosmic ray spectrum even for fairly faint sources. Discriminating a cosmic ray spectrum from a light dark matter particle will be instead much more difficult, and will require long observations and/or a bright source.

We present a new approach to measure the mass of a super-massive black hole (SMBH) located at the center of a giant elliptical galaxy. This method applies the well-known technique of using the hot, X-ray emitting plasma as a tracer of the large-scale gravitational potential of a giant galaxy (or galaxy cluster) and extends it far down into the central region of a galaxy using high-resolution X-ray data from the Chandra X-ray Observatory. We report the first detection of a SMBH using this method in the Virgo elliptical galaxy, NGC 4649, and present results of preliminary detections in 3 other systems. In addition to providing interesting constraints on the black-hole masses, we show that the stellar mass-to-light ratios of the galaxies computed from this approach agree very well with the prediction from stellar population synthesis models, thus providing strong support for the underlying assumptions of the method (e.g., hydrostatic equilibrium).

We explore the feasibility and astrophysical consequences of a new long-range U(1) gauge field ("dark electromagnetism") that couples only to dark matter, not to the Standard Model. The dark matter consists of an equal number of positive and negative charges under the new force, but annihilations are suppressed if the dark matter mass is sufficiently high and the dark fine-structure constant is sufficiently small. The correct relic abundance can be obtained if the dark matter also couples to the conventional weak interactions, and we verify that this is consistent with particle-physics constraints. The primary limit on comes from the demand that the dark matter be effectively collisionless in galactic dynamics, which implies for TeV-scale dark matter. These values are easily compatible with constraints from structure formation and primordial nucleosynthesis. We raise the prospect of interesting new plasma effects in dark matter dynamics, which remain to be explored. This proceedings is based on the work presented originally in.¹

The Hubble relation between distance and redshift is a purely cosmographic relation that depends only on the symmetries of a FLRW spacetime, but does not intrinsically make any dynamical assumptions. This suggests that it should be possible to estimate the parameters defining the Hubble relation without making any dynamical assumptions. To test this idea, we perform a number of inter-related cosmographic fits to the legacy05 and gold06 supernova datasets, paying careful attention to the systematic uncertainties. Based on this supernova data, the "preponderance of evidence" certainly suggests an accelerating universe. However we would argue that (unless one uses additional dynamical and observational information, and makes additional theoretical assumptions) this conclusion is not currently supported "beyond reasonable doubt". As part of the analysis we develop two particularly transparent graphical representations of the redshift-distance relation — representations in which acceleration versus deceleration reduces to the question of whether the relevant graph slopes up or down.

We report on the results of two successful, simultaneous observations of Sagittarius A* at the center of the Milky Way. The observations were carried out in 2004 and 2008 using telescopes operating from the mm-radio domain to the X-ray domain, and detected strong flux density variations in all wavelength bands. Modeling suggests that a combination of a synchrotron self Compton process and an adiabatic expansion of source components are at work. The luminous flare emission of Sagittarius A* also supports the presence of an accreting super massive black hole at that position. We also discuss the potential of NIR interferometry for further detailed investigations of the accretion process in SgrA*.

We announce the public release of the 'dark' stellar evolution code DarkStars. The code simultaneously solves the equations of WIMP capture and annihilation in a star with those of stellar evolution assuming approximate hydrostatic equilibrium. DarkStars includes the most extensive WIMP microphysics of any dark evolution code to date. The code employs detailed treatments of the capture process from a range of WIMP velocity distributions, as well as composite WIMP distribution and conductive energy transport schemes based on the WIMP mean-free path in the star. We give a brief description of the input physics and practical usage of the code, as well as examples of its application to dark stars at the Galactic centre.

Studies of the inner few parsecs at the Galactic Centre provide evidence of a 4×10⁶M_ʘ supermassive black hole, associated with the unusual, variable radio and infrared source Sgr A*.

Our major aim is the study and analysis of the physical processes responsible for the variable emission from the compact radio source Sgr A*. In order to understand the physics behind the observed variability, we model the time evolution of the flare emitting region by studying light curves and spectra of emission originating at the surface of the accretion disk, close to the event horizon, near the marginally stable orbit of a rotating black hole.

Here we discuss the methods used in the analysis of the time-variable spectral features and subsequently present preliminary modeling results.

After summarizing the respective merits of the Cold Dark Matter (CDM) and Modified Newtonian Dynamics (MOND) paradigms in various stellar systems, we investigate the possibility that a non-standard interaction between baryonic matter and dark matter could reproduce the successes of CDM at extragalactic scales while making baryonic matter effectively obey the MOND field equation in spiral galaxies.

We use a high-resolution simulation of a galaxy-sized dark matter halo, published simulated data as well as four cluster-sized haloes¹ to study the inner halo structure in a Lambda cold dark matter cosmology. We find that the circular velocity curves are substantially better described by SWTS^2,3 profiles than by NFW⁴ or Moore⁵ profiles. Our findings confirm that no asymptotic slope is reached and that the corresponding extrapolated density profiles reach a finite maximum density. We analyse the impact of our findings on the detectability of the gamma-ray signal from the central regions of the Milky Way (MW) and from dark matter substructures in its halo, if the dark matter in the Universe is made of weakly self-interacting particles which self-annihilate. We discuss detection strategies for current gamma-ray detectors. We in addition review recent work by other authors and comment on possible boosts due to effects of structure on very small scales.

The primordial molecules, which appear during the phase of cosmological recombination, play an important role in the mechanisms of formation of the first gravitational structures. Their thermal influence on the gravitational dynamics of collapse can generate, under certain conditions, an instability which leads to the fragmentation of the initial collapsing structure. In this framework it is crucial to establish the initial conditions of the mechanism of gravitational collapse, in particular the abundances of molecules susceptible to have a thermal influence as the primordial molecules.

In a Universe made of baryonic and non-baryonic dark matter, we need to discuss how each component couples with the other, and how this coupling may modify the primordial chemistry during the gravitational growth of structures. Since dark matter is assumed to be affected only by gravity and is collisionless, there is no effective pressure term in its equation of evolution. The linearized continuity equation in Fourier modes describes the dark matter and baryon fluids by two second-order differential equations which couple the baryon chemistry and gas dynamics to dark-matter by gravity.

In this contribution besides to remind the chemical processes in the early Universe, we shall analyze the influence that these last ones can have on the formation of the first baryonic structures gravitational. Thus, we present calculations in the linear approximation of density fluctuations, but in the full non-linear regime of chemical abundances about the primordial molecule formation in a uniform medium perturbed by small density inhomogeneities at various spatial wavelengths. We analyze the differential abundances of the primordial molecules H₂, HD and LiH. As the Universe expands, the baryonic fluctuations increase and induce strong contrasts on the primordial molecular abundances.

The main result is that the chemical abundances at the transition between the linear and non-linear regimes of density fluctuations (such as in proto-collapsing structures) are already very inhomogeneous and scale dependent. These results indicate that pronounced inhomogeneous chemical abundances are present already before and during the dark age. This must have a direct consequence on the mass spectrum of the first bound objects since gas cooling depends then mainly on the particular abundances of H₂ and HD.

Flat or almost flat rotation curves of spiral galaxies can be explained by logarithmic gravitational potentials. The field equations of GR admit of spacetime metrics with such behaviors. The scenario can be interpreted either as an alternative theory of gravitation or, equivalently, as a dark matter paradigm. In the latter interpretation, one is led to assign a dark companion to the baryonic matter who's size and distribution is determined by the mass of the baryons. The formalism also opens up a way to support Milgrom's idea that the acceleration of a test object in a gravitational field is not simply the newtonian gravitational force g_N, but rather an involved function of (g_N/a₀), a₀ MOND's universal acceleration.

The approach^1-4 unifying all the internal degrees of freedom—the family quantum number, the spin and all the charges into only two kinds of the spin— is offering a new way of understanding the properties of quarks and leptons: not only their charges and their connection to the corresponding gauge fields but also the appearance of families and the Yukawa couplings. In this talk I present a simple starting Lagrange density for a spinor—carrying in d = 1+13 only two kinds of the spin, no charges, and interacting with the corresponding gauge fields—the vielbeins and the two kinds of spin connection fields. The way of breaking the starting symmetries determines the observed properties of the families of spinors and of the gauge fields, predicting that there are four families at low energies and that a much heavier fifth family with zero Yukawa couplings to the lower four families, might, by forming baryons in the evolution of the universe, contribute a major part to the dark matter. I report on the limitations that the cosmological and the direct experimental evidences might put on this stable family of quarks and leptons.

We analyze some generic properties of the dark energy (DE) perturbations, in the case of a self-conserved DE fluid. We also apply a simple test (the "F-test") to compare a model to the data on large scale structure (LSS) under the assumption of negligible DE perturbations. We exemplify our discussions by means of the ΛXCDM model, showing that it provides a viable solution to the cosmological coincidence problem.

I discuss potential observational tests of a "radically conservative" solution to the problem of dark energy in cosmology, in which the apparent acceleration of the universe is understood as a consequence of gravitational energy gradients that grow when spatial curvature gradients become significant with the nonlinear growth of cosmic structure. In particular, I discuss measures equivalent to the dark energy equation of state, baryon acoustic oscillation statistic D_V, H(z), the Om(z) diagnostic, an average inhomogeneity diagnostic, and the time–drift of cosmological redshifts.

The study of time-lags in light curves of cosmological sources such as Gamma-Ray Bursts and Active Galaxies, as a function of energy and redshift of the source, may lead to a detection of Lorentz Symmetry breaking or effects due to Quantum Gravity in extra-dimensions or Loop Quantum Gravity models. In this paper, the recent time-of-flight studies with photons published by the space and ground based experiments are reviewed. Various methods used in the time delay searches are described, and their performance discusseed. Since no significant time-lag value was found within experimental precision of the maesurements, the 95% Confidence Level limit on the Quantum Gravity scale of the order of 10¹⁶GeV and 10¹⁸GeV for the linear term in the standard photon dispersion relations, were established from the Gamma-Ray Burst and Active Galaxy data respectively.

Using two complementary X-ray galaxy cluster studies we present new constraints on dark energy and modified gravity. Using Chandra measurements of the X-ray gas mass fraction, f_gas, in 42 hot, X-ray luminous, dynamically relaxed clusters spanning the redshift range 0.05 < z < 1.1, we obtain a tight constraint on the mean matter density and a detection of the effects of dark energy on the distances to the clusters comparable in significance to recent type Ia supernovae (SNIa) studies. Using measurements of the growth of cosmic structure, as inferred from the observed evolution of the X-ray luminosity function (XLF) of clusters, we obtain the first precise determination of the dark energy equation of state and constrain departures from General Relativity (GR) on cosmological scales. For the latter, we employ the growth rate parameterization, Ω_m(z)^γ, for which GR predicts a growth index γ ~ 0.55. Combining the XLF with observations of the cosmic microwave background, SNIa, and f_gas, to simultaneously constrain a flat cosmological constant (ΛCDM) background model, we obtain , which is consistent with GR. Both the f_gas and XLF analyses provide strong, independent support to the GR+ΛCDM paradigm.

I show two observational projects I am involved in, which are aimed at understanding better the existence and nature of dark matter, and also aimed at testing alternatives to galactic dark matter such as MOND (Modified Newtonian Dynamics). I present new HI observations of the nearby dwarf galaxy NGC 3741. This galaxy has an extremely extended HI disc (42 B-band exponential scalelengths). The distribution and kinematics are accurately derived by building model data cubes, which closely reproduce the observations. Mass modelling of the rotation curve shows that a cored dark matter halo or MOND provide very good fits, whereas Cold Dark Matter density profiles fail to fit the data. I also show new results about tidal dwarf galaxies, which within the CDM framework are expected to be dark matter-free but whose kinematics instead show a mass discrepancy, exactly of the magnitude that is expected in MOND (Modified Newtonian Dynamics).

The Elko field of Ahluwalia and Grumiller is a quantum field for massive spin-1/2 particles. It has been suggested as a candidate for dark matter. We discuss our attempts to interpret the Elko field as a quantum field in the sense of Weinberg. Our work suggests that one should investigate quantum fields based on representations of the full Poincaré group which belong to one of the non-standard Wigner classes.

The annihilations of WIMPs produce high energy gamma-rays in the final state. These high energy gamma-rays may be detected by imaging atmospheric Cherenkov telescopes (IACTs). Amongst the plausible targets are the Galactic Center, the centre of galaxy clusters, dwarf Sphreroidal galaxies and substructures in Galactic haloes. I will review on the recent results from observations of ongoing IACTs.

A search for a dark matter (DM) annihilation signal into γ-rays towards the direction of the Canis Major (CMa) overdensity has been performed with the HESS telescopes. The nature of CMa is still controversial and one scenario represents it as a dwarf galaxy, making it an interesting candidate for DM annihilation searches. A total of 9.6 hours of high quality data were collected with the H.E.S.S. array of Imaging Atmospheric Cherenkov Telescopes (IACTs) and no evidence for a very high energy γ-ray signal was found. Constraints on the velocity-weighted annihilation cross section 〈σv〉 are calculated for specific WIMP scenarios, using a NFW model for the DM halo profile and taking advantage of numerical simulations of hierarchical structure formation. 95% C.L. exclusion limits of the order of 5 × 10^-24 cm³ s^-1 are reached in the 500 GeV - 10 TeV WIMP mass range.

IceCube is a neutrino telescope currently under construction at the geographical S. Pole. It will be a cubic kilometer size by 2011 when complete. So far IceCube has been successful in both deploying strings and taking data with its partial detector together with its predecessor, AMANDA. Its performance was well verified as it was originally designed. Here we present some interesting recent results from IceCube and AMANDA: point source search, GRB080319B, indirect dark matter search, magnetic monopole search and search for violation of Lorentz invariance. The IceCube deep core which will consist of 6 special strings is expected to improve low energy physics of IceCube such as indirect dark matter search.

If non-baryonic dark matter exists in the form of neutralinos, a neutrino flux is expected from the decay of neutralino pair annihilation products inside heavy celestial bodies. Data taken with the AMANDA (Antarctica Muon and Neutrino Detector Array) neutrino telescope located at the South Pole have been used in a search for this indirect dark matter signal. We present result from searches for neutralinos accumulated in the Sun and in the centre of the Earth, using the data taken up to 2003.

The IceCube neutrino detector is being deployed at the South Pole since 2006. This cubic kilometer observatory with 80 strings of 60 photomultipliers will be completed in 2011. The data taken in 2007 with 22 strings have been used in the search for neutrino signal from neutralinos in the Sun. Preliminary results of this analysis will be shown. The planned IceCube detector will be complemented with a dense inner core, Deep Core, to improve the sensitivity in the GeV-TeV energy domain. We will also discuss the expected performance of the combined IceCube - Deep Core detector in relation to dark matter searches.

ANTARES (Astronomy with a Neutrino Telescope and Abyss environmental RESearch) is currently the largest neutrino detector on the Northern Hemisphere. The detector consists of twelve lines, carrying 885 ten-inch photomultipliers in total, placed at a depth of about 2480 meters in the Mediterranean Sea near Toulon, France. The PMTs detect Cherenkov light emitted by muons from neutrino charged current interactions in the surrounding seawater and the rock below. The neutrinos momentum is transferred to the muons allowing for reconstruction of the neutrinos direction. The goals of ANTARES are among others the search for astrophysical neutrino point sources and for neutrinos produced in self-annihilation of dark matter particles. A likely source of the latter type of neutrino emission would be the Sun, where dark matter particles from the galactic halo are expected to accumulate. ANTARES is taking data with its full twelve line configuration since May 2008, and has been before in a five and ten line setup for more than a year. First results on the search for dark matter annihilation in the Sun, and their interpretation in the framework of mSugra are presented, as well as sensitivity studies on Dark Matter search with the full ANTARES detector and the future large undersea KM3NeT neutrino telescope.

In this talk we present data analysis methods for reconstructing the mass and couplings of Weakly Interacting Massive Particles (WIMPs) by using directly future experimental data (i.e., measured recoil energies) from direct Dark Matter detection. These methods are independent of the model of Galactic halo as well as of WIMPs. The basic ideas of these methods and the feasibility and uncertainties of applying them to direct detection experiments with the next generation detectors will be discussed.

It is now well established that roughly 25% of the total mass-energy density of the Universe is in the form of non-relativistic particles referred to as Dark Matter. This paper will review various ongoing Dark Matter searches and the variety of techniques and implementation used to both detect the rare Dark Matter interactions as well as reject the vast number of background events, with focus given to the recent results obtained in this past year. Eight years into the 21^st century, the field Dark Matter searches is very active, with many new experimental results, and some intriguing hints.

An active veto detector to complement the ZEPLIN-III two phase Xenon, direct dark matter device is described. The design consists of 52 plastic scintillator segments, individually read out by high efficiency photomultipliers, coupled to a Gd loaded passive polypropylene shield. Experimental work was performed to determine the plastic scintillator characteristics which were used to inform a complete end-to-end Monte Carlo simulation of the expected performance of the new instrument, both operating alone and as an active veto detector for ZEPLIN-III. The veto device will be capable of tagging over 65% of expected coincident nuclear recoil events in the energy range of interest in ZEPLIN-III, and over 14% for gamma ray rejection (gamma and neutron rate is predicted by simulation), while contributing no significant additional background. In addition it will also provide valuable diagnostic capabilities. The inclusion of the veto to ZEPLIN-III will aid to significantly improve the sensitivity to spin independent WIMP-nucleon cross sections ~10^-9 pb.

Current proposed photon rocket designs include the Nuclear Photonic Rocket and the Antimatter Photonic Rocket (proposed by Eugen Sanger in the 1950s, as reported by Ref. 1). This paper examines the feasibility of improving the thrust of photon-driven ramjet propulsion by using DM rocket propulsion. The open question is: would a heavy WIMP, if converted to photons, upgrade the power (thrust) of a photon rocket drive, to make interstellar travel a feasible proposition?

The following sections are included:

• LIST OF PARTICIPANTS, DARK2009

• AUTHORS INDEX