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We briefly review some recent Cold Dark Matter (CDM) models. Our main focus are charge symmetric models of WIMPs which are not the standard SUSY LSP's (Lightest Supersymmetric Partners). We indicate which experiments are most sensitive to certain aspects of the models. In particular, we discuss the manifestations of the new models in neutrino telescopes and other setups. We also discuss some direct detection experiments and comment on measuring the direction of recoil ions — which is correlated with the direction of the incoming WIMP. This could yield daily variations providing along with the annual modulation signatures for CDM.
In this paper, we have discussed a (1 + 9)-dimensional open cosmological model motivated from N = 2 maximal supergravity arguments characterized by the presence of a wormhole connected to the extra dimensions part and a Gauss–Bonnet (GB) curvature corrections. The universe is dominated by dark energy and cold dark matter (CDM) which emerged from extra dimensions as supported by recent phenomenological and observational arguments. By assuming that the wormhole in the outer/inner regions of the halos of galaxies is characterized by a CDM profile density, it was revealed that the universe is expanding acceleratedly with time, dominated by a microscopic traversable wormhole and dark energy. The role of the dominance of the GB term is discussed and the model is confronted with astrophysical observations.
The Lambda-Cold Dark Matter (ΛCDM) model describes successfully our Universe on large scales, as has been verified by a wide range of observations. A number of apparent inconsistencies have arisen between observations and ΛCDM predictions on small scales. In this work, the current status of observations on galactic and subgalactic scales is reviewed. Theoretical predictions and recent observations are brought together in order to reveal the nature and severity of the inconsistencies. Lastly, the progress towards the resolution of each one of these conflicts is briefly reviewed.
The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat universe. Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle (LSP). Thus direct dark matter detection is central to particle physics and cosmology. Most of the research on this issue has hitherto focused on the detection of the recoiling nucleus. In this paper, we study transitions to the excited states, focusing on the first excited state at 50 keV of Iodine A=127. We find that the transition rate to this excited state is ≼10 percent of the transition to the ground state. So, in principle, the extra signature of the gamma ray following its de-excitation can be exploited experimentally.
The purpose of this paper is to contribute to understanding innovation dynamics in services, in particular the link between innovation and productivity. A methodology to explain this link is suggested. Instead of establishing a single, direct connection between innovation and labor productivity, as in earlier approaches in the services literature, a simultaneous equations model is used. We put forward an extended version of the CDM (Crepon, Duguet and Mairesse) model, incorporating two feedback effects and using innovation activities rather than the more restrictive R&D proxy. Activities prior to the innovation implementation are also taken into account allowing for direct and indirect effects on labor productivity. Moreover, we discuss and handle the oftentimes overlooked methodological problems affecting this relationship. Micro data for ten service sectors in Portugal are used to estimate the model. The existence of a Schumpeterian virtuous cycle is confirmed, pointing to a mechanism reinforcing innovation investment returns. We find that innovation activities have a positive impact on labor productivity, but no evidence was found of a significant direct effect of innovation output. Labor productivity also improves with management capabilities. Relationships with customers, suppliers and cooperation partnerships significantly increase the probability of innovating, suggesting that stimulating organizational networking is a key element in a service firm’s innovation strategy.
We apply the central extension technique of Poincaré to dynamics involving an interacting mixture of pressureless matter and vacuum near a finite-time singularity. We show that the only attractor solution on the circle of infinity is the one describing a vanishing matter-vacuum model at early times.
We review various issues related to the direct detection of constituents of dark matter, which are assumed to be Weakly Interacting Massive Particles (WIMPs). We specifically consider heavy WIMPs such as: 1) The lightest supersymmetric particle LSP or neutralino. 2) The lightest Kaluza-Klein particles in theories of extra dimensions and 3) other extensions of the standard model. In order to get the event rates one needs information about the structure of the nucleon as well as as the structure of the nucleus and the WIMP velocity distribution. These are also examined Since the expected event rates for detecting the recoiling nucleus are extremely low and the signal does not have a characteristic signature to discriminate against background we consider some additional aspects of the WIMP nucleus interaction, such as the periodic behavior of the rates due to the motion of Earth (modulation effect). Since, unfortunately, this is characterized by a small amplitude we consider other options such as directional experiments, which measure not only the energy of the recoiling nuclei but their direction as well. In these, albeit hard, experiments one can exploit two very characteristic signatures: a)large asymmetries and b) interesting modulation patterns. Furthermore we extended our study to include evaluation of the rates for other than recoil searches such as: i) Transitions to excited states, ii) Detection of recoiling electrons produced during the neutralino-nucleus interaction and iii) Observation of hard X-rays following the de-excitation of the ionized atom.
Scientific research confirms that humans have caused most of climate change in recent decades. Climate change will continue, at a pace determined by the past, present, and future emissions of heat-trapping gases, namely Carbon Dioxide (CO2), Sulfur Dioxide (SO2) and Nitrogen Dioxide those will is expected to cause large amounts of warming in the future and reducing emissions has become one of the main goals of developed countries since the Kyoto Protocol signing in 1997. A market for emission allowances, often called “carbon markets”, has been created which has shown an interesting dynamic in the last decade. Futures markets emission allowances were introduced at the “Chicago Climate Futures Exchange” in 2004, and at the “European Climate Exchange” in 2005. Unusually Europe has been the driver of regulation and innovation in the global climate change arena. Carbon markets were not immune to the economic crisis and in the past 5 years have shown enormous volatility and were even completely delisted in the U.S. market.
Greenhouse gas (GHG) emissions are largely determined by howenergy is created and used, and policies designed to encourage mitigation efforts reflect this reality. An unintended consequence of an energy-focused strategy is that the set of policy instruments needed to tap mitigation opportunities in agriculture is incomplete. In particular, market-linked incentives to achieve mitigation targets are disconnected from efforts to better manage carbon sequestered in agricultural land. This is especially important for many countries in Eastern Europe and Central Asia (ECA) where once-productive land has been degraded through poor agricultural practices. Often good agricultural policies and prudent natural resource management can compensate for missing links to mitigation incentives, but only partially.At the same time, two international project-based programs, Joint Implementation (JI) and the Clean Development Mechanism (CDM), have been used to finance other types of agricultural mitigation effortsworldwide. However, a reviewof projects suggests that fewECAcountries take full advantage of these financing paths. This chapter discusses mitigation opportunities in the region, the reach of current mitigation incentives, and missed mitigation opportunities in agriculture. The chapter concludes with a discussion of alternative policies designed to jointly promote mitigation and co-benefits for agriculture and the environment.
Current theories about the Universe based on an FLRW model conclude that it is composed of ~4% normal matter, ~28 % dark matter and ~68% Dark Energy which is responsible for the well-established accelerated expansion: this model works extremely well. As the Universe expands the density of normal and dark matter decreases while the proportion of Dark Energy increases. This model assumes that the amount of dark matter, whose nature at present is totally unknown, has remained constant. This is a natural assumption if dark matter is a particle of some kind – WIMP, sterile neutrino, lightest supersysmmetric particle or axion, etc. – that must have emerged from the early high temperature phase of the Big Bang. This paper proposes that dark matter is not a particle such as these but a vacuum effect, and that the proportion of dark matter in the Universe is actually increasing with time. The idea that led to this suggestion was that a quantum process (possibly the Higgs mechanism) might operate in the nilpotent vacuum that Rowlands postulates is a dual space to the real space where Standard Model fundamental fermions (and we) reside. This could produce a vacuum quantum state that has mass, which interacts gravitationally, and such states would be ‘dark matter’. It is proposed that the rate of production of dark matter by this process might depend on local circumstances, such as the density of dark matter and/or normal matter. This proposal makes the testable prediction that the ratio of baryonic to dark matter varies with redshift and offers an explanation, within the framework of Rowlands' ideas, of the coincidence problem – why has cosmic acceleration started in the recent epoch at redshift z ~0.55 when the Dark Energy density first became equal to the matter density?. This process also offers a potential solution to the ‘missing baryon’ problem.