Sterile neutrino dark matter in warped extra dimensions

We consider a (long-lived) sterile neutrino dark matter scenario in a five dimensional (5D) warped extra dimension model where the fields can live in the bulk, which is partly motivated from the absence of the absolutely stable particles in a simple Randall-Sundrum model. The dominant production of the sterile neutrino can come from the decay of the radion (the scalar field representing the brane separation) around the electroweak scale. The suppressions of the 4D parameters due to the warp factor and the small wave function overlaps in the extra dimension help alleviate the exceeding fine-tunings typical for a sterile neutrino dark matter scenario in a 4D setup.Comment: Typos corrected and references adde

Flow visualization of mean and coherent flow structures around T-type and L-type groynes

River hydrodynamicsTurbulent open channel flow and transport phenomen

Positrons in Cosmic Rays from Dark Matter Annihilations for Uplifted Higgs Regions in MSSM

We point out that there are regions in the MSSM parameter space which successfully provide a dark matter (DM) annihilation explanation for observed positron excess (e.g. PAMELA), while still remaining in agreement with all other data sets. Such regions (e.g. the uplifted Higgs region) can realize an enhanced neutralino DM annihilation dominantly into leptons via a Breit-Wigner resonance through the CP-odd Higgs channel. Such regions can give the proper thermal relic DM abundance, and the DM annihilation products are compatible with current antiproton and gamma ray observations. This scenario can succeed without introducing any additional degrees of freedom beyond those already in the MSSM.Comment: 11 pages, 9 figure

A Stochastic Model of Fragmentation in Dynamic Storage Allocation

We study a model of dynamic storage allocation in which requests for single units of memory arrive in a Poisson stream at rate λ and are accommodated by the first available location found in a linear scan of memory. Immediately after this first-fit assignment, an occupied location commences an exponential delay with rate parameter μ, after which the location again becomes available. The set of occupied locations (identified by their numbers) at time t forms a random subset St of {1,2, . . .}. The extent of the fragmentation in St, i.e. the alternating holes and occupied regions of memory, is measured by (St) - |St |. In equilibrium, the number of occupied locations, |S|, is known to be Poisson distributed with mean ρ = λ/μ. We obtain an explicit formula for the stationary distribution of max (S), the last occupied location, and by independent arguments we show that (E max (S) - E|S|)/E|S| → 0 as the traffic intensity ρ → ∞. Moreover, we verify numerically that for any ρ the expected number of wasted locations in equilibrium is never more than 1/3 the expected number of occupied locations. Our model applies to studies of fragmentation in paged computer systems, and to containerization problems in industrial storage applications. Finally, our model can be regarded as a simple concrete model of interacting particles [Adv. Math., 5 (1970), pp. 246–290]

Survival of technologies: an evolutionary game approach

This paper models technology adoption as an evolutionary and asymmetric game based on a pairwise contest involving two populations, firms and consumers. First, externalities are considered only on the supply side, leading to the usual results found in the recent economic literature on the subject: path dependence, lock-in, and the possibility ofselecting inferior technology. Next externalities are introduced on the demand side, which in Leibenstein's classic paper leads to bandwagon and snob effects, and interactions between supply and demand are examined

Scale and externalities in an evolutionary game model

Este artigo discute o processo de seleção de escalas de produção em um modelo de jogo evolucionário no qual os requisitos de racionalidade são muito limitados

Parameterizing the Power Spectrum: Beyond the Truncated Taylor Expansion

The power spectrum is traditionally parameterized by a truncated Taylor series: $ln P(k) = ln P_* + (n_*-1) ln(k/k_*) + {1/2} n'_* ln^2(k/k_*)$. It is reasonable to truncate the Taylor series if $|n'_* ln(k/k_*)| << |n_*-1|$, but it is not if $|n'_* ln(k/k_*)| \gtrsim |n_*-1|$. We argue that there is no good theoretical reason to prefer $|n'_*| << |n_*-1|$, and show that current observations are consistent with $|n'_* ln(k/k_*)| ~ |n_*-1|$ even for $|ln(k/k_*)| ~ 1$. Thus, there are regions of parameter space, which are both theoretically and observationally relevant, for which the traditional truncated Taylor series parameterization is inconsistent, and hence it can lead to incorrect parameter estimations. Motivated by this, we propose a simple extension of the traditional parameterization, which uses no extra parameters, but that, unlike the traditional approach, covers well motivated inflationary spectra with $|n'_*| ~ |n_*-1|$. Our parameterization therefore covers not only standard-slow-roll inflation models but also a much wider class of inflation models. We use this parameterization to perform a likelihood analysis for the cosmological parameters.Comment: References added. Typo correcte

Palonosetron compared with ondansetron in pediatric cancer patients: multicycle analysis of a randomized Phase III study

Aim: To investigate across multiple cycles the efficacy and safety of palonosetron in the prevention of chemotherapy-induced nausea and vomiting in pediatric cancer patients receiving highly or moderately emetogenic chemotherapy (HEC/MEC). Patients & methods: Patients were randomly assigned to 10, 20 mu g/kg palonosetron or 3 x 150 mu g/kg ondansetron for up to four cycles of HEC/MEC. Results: In all on-study chemotherapy cycles, complete response rates were higher in patients in the 20 mu g/kg palonosetron group than the ondansetron group. Treatment-emergent adverse events were comparable between the palonosetron 20 mu g/kg and ondansetron groups. Conclusion: Over four cycles of HEC/MEC, 20 mu g/kg palonosetron was an efficacious and safe treatment for the prevention of chemotherapy-induced nausea and vomiting in pediatric cancer patients

Optical evidence for symmetry changes above the Neel temperature in KCuF3

We report on optical measurements of the 1D Heisenberg antiferromagnet KCuF3. The crystal-field excitations of the Cu2+ ions have been observed and their temperature dependence can be understood in terms of magnetic and exchange-induced dipole mechanisms and vibronic interactions. Above T_N we observe a new temperature scale T_S characterized by the emergence of narrow absorption features that correlate with changes of the orbital ordering as observed by Paolasini et al. [Phys. Rev. Lett. 88, 106403 (2002)]. The appearance of these optical transitions provides evidence for a symmetry change above the Neel temperature that affects the orbital ordering and paves the way for the antiferromagnetic ordering.Comment: 4 pages, 2 figure

From the Spectrum to Inflation : An Inverse Formula for the General Slow-Roll Spectrum

We propose a general inverse formula for extracting inflationary parameters from the observed power spectrum of cosmological perturbations. Under the general slow-roll scheme, which helps to probe the properties of inflation in a model independent way, we invert the leading order, single field, power spectrum formula. We also give some physically interesting examples to demonstrate its wide applicability and illuminate its properties.Comment: 8 pages, no figure ; References expande