46,363 research outputs found

    Model-checking Quantitative Alternating-time Temporal Logic on One-counter Game Models

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    We consider quantitative extensions of the alternating-time temporal logics ATL/ATLs called quantitative alternating-time temporal logics (QATL/QATLs) in which the value of a counter can be compared to constants using equality, inequality and modulo constraints. We interpret these logics in one-counter game models which are infinite duration games played on finite control graphs where each transition can increase or decrease the value of an unbounded counter. That is, the state-space of these games are, generally, infinite. We consider the model-checking problem of the logics QATL and QATLs on one-counter game models with VASS semantics for which we develop algorithms and provide matching lower bounds. Our algorithms are based on reductions of the model-checking problems to model-checking games. This approach makes it quite simple for us to deal with extensions of the logical languages as well as the infinite state spaces. The framework generalizes on one hand qualitative problems such as ATL/ATLs model-checking of finite-state systems, model-checking of the branching-time temporal logics CTL and CTLs on one-counter processes and the realizability problem of LTL specifications. On the other hand the model-checking problem for QATL/QATLs generalizes quantitative problems such as the fixed-initial credit problem for energy games (in the case of QATL) and energy parity games (in the case of QATLs). Our results are positive as we show that the generalizations are not too costly with respect to complexity. As a byproduct we obtain new results on the complexity of model-checking CTLs in one-counter processes and show that deciding the winner in one-counter games with LTL objectives is 2ExpSpace-complete.Comment: 22 pages, 12 figure

    Non-equilibrium effects on particle freeze-out in the early universe

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    We investigate the possible effects that deviations from kinetic equilibrium can have on massive particles as they decouple from chemical equilibrium. Different methods of solving the Boltzmann equation yield significantly different relic number densities of such particles. General considerations concerning the Dirac or Majorana structure of the particles are discussed. It is shown that non-equilibrium effects are small for particles decoupling while strongly non-relativistic, as will be the case for most cold dark matter candidates.Comment: 9 pages REVTEX, to appear in New Astronom

    Results of the SDHCAL technological prototype

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    The SDHCAL technological prototype that has been completed in 2012 was exposed to beams of pions and electrons of different energies at the CERN SPS for a total time period of 5 weeks. The data has been analyzed within the CALICE collaboration. Preliminary results indicate that a highly granular hadronic calorimeter conceived for PFA application is also a powerful tool to separate pions from electrons. The SDHCAL provides also a very good resolution of hadronic showers energy measurement. The use of multi-threshold readout mode shows a clear improvement of the resolution at energies exceeding 30 GeV with respect to the binary readout mode. Simulations of the pion interactions in the SDHCAL are presented and new ideas to improve on the energy resolution using the topology of hadronic showers are mentioned.Comment: Talk presented at the International Workshop on Future Linear Colliders (LCWS13), Tokyo, Japan, 11-15 November 201

    Neutrino physics from Cosmology

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    In recent years precision cosmology has become an increasingly powerful probe of particle physics. Perhaps the prime example of this is the very stringent cosmological upper bound on the neutrino mass. However, other aspects of neutrino physics, such as their decoupling history and possible non-standard interactions, can also be probed using observations of cosmic structure. Here, I review the current status of cosmological bounds on neutrino properties and discuss the potential of future observations, for example by the recently approved EUCLID mission, to precisely measure neutrino properties.Comment: 8 pages, 2 figures, to appear in the proceedings of Pontecorvo100 - Symposium in honour of Bruno Pontecorv

    Cosmological bounds on masses of neutrinos and other thermal relics

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    With the advent of precision data, cosmology has become an extremely powerful tool for probing particle physics. The prime example of this is the cosmological bound on light neutrino masses. Here I review the current status of cosmological neutrino mass bounds as well as the various uncertainties involved in deriving them. From WMAP, SDSS, and Lyman-alpha forest data an upper bound on the sum of neutrino masses of 0.65 eV (95% C.L.) can be derived with any assumptions about bias. I also present new limits on other light, thermally produced particles. For example, a hypothetical new Majorana fermion decoupling around the electroweak phase transition must have m < 5 eV.Comment: 10 pages, 3 figures, to appear in SeeSaw '25 proceedings, references update

    Neutrino cosmology - an update

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    Present cosmological observations yield an upper bound on the neutrino mass which is significantly stronger than laboratory bounds. However, the exact value of the cosmological bound is model dependent and therefore less robust. Here, I review the current status of cosmological neutrino mass bounds and also discuss implications for sterile neutrinos and LSND in particular.Comment: Invited talk at Thinking, observing, and mining the universe, Sorrento, Italy (22-27 September 2003
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