Magnetic field generation in Higgs inflation model

We study the generation of magnetic field in Higgs-inflation models where the Standard Model Higgs boson has a large coupling to the Ricci scalar. We couple the Higgs field to the Electromagnetic fields via a non- renormalizable dimension six operator suppressed by the Planck scale in the Jordan frame. We show that during Higgs inflation magnetic fields with present value $10^{-6}$ Gauss and comoving coherence length of $100 kpc$ can be generated in the Einstein frame. The problem of large back-reaction which is generic in the usual inflation models of magneto-genesis is avoided as the back-reaction is suppressed by the large Higgs-curvature coupling.Comment: 10 pages, RevTeX

On the Naturalness of Higgs Inflation

We critically examine the recent claim that the Standard Model Higgs boson ${\cal H}$ could drive inflation in agreement with observations if $|{\cal H}|^2$ has a strong coupling $\xi\sim 10^4$ to the Ricci curvature scalar. We first show that the effective theory approach upon which that claim is based ceases to be valid beyond a cutoff scale $\Lambda=m_p/\xi$, where $m_p$ is the reduced Planck mass. We then argue that knowing the Higgs potential profile for the field values relevant for inflation ($|{\cal H}|>m_p/\sqrt{\xi}\gg \Lambda$) requires knowledge of the ultraviolet completion of the SM beyond $\Lambda$. In absence of such microscopic theory, the extrapolation of the pure SM potential beyond $\Lambda$ is unwarranted and the scenario is akin to other ad-hoc inflaton potentials afflicted with significant fine-tuning. The appealing naturalness of this minimal proposal is therefore lost.Comment: 9 pages. Replaced with published version, plus a footnote clarifying the use of power counting estimate

Circumventing the eta problem in building an inflationary model in string theory

The eta problem is one of the most significant obstacles to building a successful inflationary model in string theory. Planck mass suppressed corrections to the inflaton potential generally lead to inflaton masses of order the Hubble scale and generate contributions of order unity to the eta slow roll parameter rendering prolonged slow roll inflation impossible. We demonstrate the severity of this problem in the context of brane anti-brane inflation in a warped throat of a Calabi-Yau flux compactification with all phenomenologically dangerous moduli stabilized. Using exact numerical solutions we show that the eta problem can be avoided in scenarios where the inflaton is non-minimally coupled to gravity and has Dirac-Born-Infeld (DBI) kinetic term. We show that the resulting cosmic microwave background (CMB) observables such as measures of non-gaussianites can, in principle, serve as a probe of scalar-gravity couplings.Comment: 8 pages, 3 figures; title changed and reference added to match published version in PR

Tau energy losses at ultra-high energy: continuous versus stochastic treatment

We study the energy losses of the tau lepton in matter through electromagnetic processes at ultra-high energy (UHE). We use both a stochastic and a continuous framework to treat these interactions and compare the flux of tau leptons propagated after some amount of matter. We discuss the accuracy of the approximation of continuous energy losses by studying the propagation in standard rock of taus with both mono-energetic and power law injection spectra.Comment: 7 pages, 8 figure

Stochastic Resonance in Ion Channels Characterized by Information Theory

We identify a unifying measure for stochastic resonance (SR) in voltage dependent ion channels which comprises periodic (conventional), aperiodic and nonstationary SR. Within a simplest setting, the gating dynamics is governed by two-state conductance fluctuations, which switch at random time points between two values. The corresponding continuous time point process is analyzed by virtue of information theory. In pursuing this goal we evaluate for our dynamics the tau-information, the mutual information and the rate of information gain. As a main result we find an analytical formula for the rate of information gain that solely involves the probability of the two channel states and their noise averaged rates. For small voltage signals it simplifies to a handy expression. Our findings are applied to study SR in a potassium channel. We find that SR occurs only when the closed state is predominantly dwelled. Upon increasing the probability for the open channel state the application of an extra dose of noise monotonically deteriorates the rate of information gain, i.e., no SR behavior occurs.Comment: 10 pages, 2 figures, to appear in Phys. Rev.

Relativistic Magnetic Monopole Flux Constraints from RICE

We report an upper limit on the flux of relativistic monopoles based on the non-observation of in-ice showers by the Radio Ice Cherenkov Experiment (RICE) at the South Pole. We obtain a 95% C.L. limit of order 10^{-18}/(cm^2-s-sr) for intermediate mass monopoles of 10^7<gamma<10^{12} at the anticipated energy E=10^{16} GeV. This bound is over an order of magnitude stronger than all previously published experimental limits for this range of boost parameters gamma, and exceeds two orders of magnitude improvement over most of the range. We review the physics of radio detection, describe a Monte Carlo simulation including continuous and stochastic energy losses, and compare to previous experimental limits.Comment: 16 pages, 6 figures. Accepted for publication in Phys. Rev. D. Minor revisions, including expanded discussion of monopole energy uncertaint

Muon-Induced Background Study for Underground Laboratories

We provide a comprehensive study of the cosmic-ray muon flux and induced activity as a function of overburden along with a convenient parameterization of the salient fluxes and differential distributions for a suite of underground laboratories ranging in depth from $\sim$1 to 8 km.w.e.. Particular attention is given to the muon-induced fast neutron activity for the underground sites and we develop a Depth-Sensitivity-Relation to characterize the effect of such background in experiments searching for WIMP dark matter and neutrinoless double beta decay.Comment: 18 pages, 28 figure

Computation using Noise-based Logic: Efficient String Verification over a Slow Communication Channel

Utilizing the hyperspace of noise-based logic, we show two string verification methods with low communication complexity. One of them is based on continuum noise-based logic. The other one utilizes noise-based logic with random telegraph signals where a mathematical analysis of the error probability is also given. The last operation can also be interpreted as computing universal hash functions with noise-based logic and using them for string comparison. To find out with 10^-25 error probability that two strings with arbitrary length are different (this value is similar to the error probability of an idealistic gate in today's computer) Alice and Bob need to compare only 83 bits of the noise-based hyperspace.Comment: Accepted for publication in European Journal of Physics B (November 10, 2010

ЕФЕКТИВНІСТЬ ІНГАЛЯЦІЙНИХ ГЛЮКОКОРТИКОСТЕРО ДІВ ПРИ РІЗНИХ ЗАПАЛЬНИХ ФЕНОТИПАХ БРОНХІАЛЬНО АСТМИУДІТЕЙ ШКІЛЬНОГО ВІКУ

In terms of clinical- epidemiologic evaluation of effectiveness of monotherapy of childhood bronchial asthma by inhalation corticosteroids, their greater effect has been determined under eosinophilic type of bronchial inflammation, but insufficiency of asthma control in presents of neutrophilic inflammatory process of airways.На основании проведенной клинико-эпидемиологической оценки эффективности монотерапии бронхиальной астмы у детей ингаляционными глюкокортикостероидами отмечено более выраженное их действие при эозинофильном типе воспаления дыхательных путей, но недостаточный уровень контролированности заболевания при нейтрофильном воспалительном ответе бронхов.На підставі проведено клініко-епідеміологічно оцінки результатів монотерапі бронхіально астми у дітей інгаляційними глюкокортикостеро дами відмічено х виразнішу клінічну ефективність при еозинофільному типі запалення дихальних шляхів, проте недостатній рівень контрольованості захворювання при нейтрофільній запальній відповіді бронхів

Use of singular classical solutions for calculation of multiparticle cross sections in field theory

A method of reducing the problem of the calculation of tree multiparticle cross sections in $\phi^4$ theory to the solution of a singular classical Euclidean boundary value problem is introduced. The solutions are obtained numerically in terms of the decomposition in spherical harmonics, and the corresponding estimates of the tree cross sections at arbitrary energies are found. Numerical analysis agrees with analytical results obtained earlier in the limiting cases of large and small energies.Comment: LaTeX, 18 pages, 3 postscript figure