1,194 research outputs found

    Primordial Bispectrum Information from CMB Polarization

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    After the precise observations of the Cosmic Microwave Background (CMB) anisotropy power spectrum, attention is now being focused on the higher order statistics of the CMB anisotropies. Since linear evolution preserves the statistical properties of the initial conditions, observed non-Gaussianity of the CMB will mirror primordial non-Gaussianity. Single field slow-roll inflation robustly predicts negligible non-Gaussianity so an indication of non-Gaussianity will suggest alternative scenarios need to be considered. In this paper we calculate the information on primordial non-Gaussianity encoded in the polarization of the CMB. After deriving the optimal weights for a cubic estimator we evaluate the Signal-to-Noise ratio of the estimator for WMAP, Planck and an ideal cosmic variance limited experiment. We find that when the experiment can observe CMB polarization with good sensitivity, the sensitivity to primordial non-Gaussianity increases by roughly a factor of two. We also test the weakly non-Gaussian assumption used to derive the optimal weight factor by calculating the degradation factor produced by the gravitational lensing induced connected four-point function. The physical scales in the radiative transfer functions are largely irrelevant for the constraints on the primordial non-Gaussianity. We show that the total (S/N)^2 is simply proportional to the number of observed pixels on the sky.Comment: To be submitted to PRD, 25 pages, 6 figure

    Contact interaction probes at the Linear Collider with polarized electron and positron beams

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    For contact-interaction searches at the Linear Collider, we discuss the advantages of polarizing both the electron and the positron beams as compared with polarizing only the electron beam. In particular, for the processes e^+e^-\to \mu^+\mu^-, \tau^+\tau^-, b\bar{b} and c\bar{c} at a future e^+e^- collider with \sqrt{s}=0.5 TeV we derive model-independent bounds on the four-fermion contact interaction parameters from studies of the helicity cross sections.Comment: 1+15 pages, LaTeX2e, including 7 figure

    New physics signatures at a Linear Collider: model-independent analysis from `conventional' polarized observables

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    We discuss four-fermion contact-interaction searches in the processes e^+e^-\to\mu^+\mu^-, c{\bar c} and b{\bar b} at a future e^+e^- Linear Collider with c.m. energy \sqrt{s}=0.5 TeV and with both beams longitudinally polarized. Our analysis is based on the measurements of familiar polarized observables such as the total cross section and the forward-backward/left-right asymmetries, and accounts for the general set of contact interaction couplings as independent, non-zero, parameters thus avoiding simplifying, model-dependent, assumptions. We derive the corresponding model-independent constraints on the above-mentioned coupling constants, and evaluate the corresponding reach at the Linear Collider, emphasizing the role of beam polarization. We compare the results with a model-dependent procedure where only one coupling is varied at a time.Comment: 13 pages, including 3 figure

    Название статьи: снижение выбросов парниковых газов через управление отходами производства

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    В настоящее время население мира растет очень быстро. Такой рост населенияспособствует высокому загрязнению окружающей среды. Сжигание углеводородного топливанеизбежно ведет к накоплению в атмосфере углекислого газа и усилению парникового эффекта.Цель исследования заключалась в оценке возможности использования в производственном циклевторичной переработки использованных ПЭТ бутылок как варианта утилизации отходов, которыйможет существенно уменьшить экологические проблемы, связанные с отходами пластиковых бутылок.Количество парниковых газов может быть сокращено за счет отказа от захоронения и сжигания впользу переработки. Переработка является экологически более предпочтительной для утилизации ПЭТ продуктов

    Contact interactions and polarized beams at a Linear Collider

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    We discuss contact-interaction searches in the processes e^+e^-\to \mu^+\mu^-, b\bar{b} and c\bar{c} at an e^+e^- Linear Collider with c.m. energy \sqrt{s}=0.5 TeV and with longitudinally polarized beams. The measurement of polarized cross sections allows to study the individual helicity cross sections, and consequently to derive separate, model-independent, constraints on the four-fermion contact interaction couplings. We evaluate the reach on those parameters foreseeable in the case of both electron and positron polarization fixed at some reference values, and compare it with the situation where only electron polarization is available. The analysis is based on polarized integrated cross sections with optimal kinematical cuts that can improve the sensitivity to the relevant couplings. While electron polarization would by itself allow such an analysis, the additional positron polarization (with no loss of beam intensity) and optimization can have a crucial role in improving the sensitivity to the new interactions.Comment: 13 pages, LaTeX, including figure

    Model-independent limits on four-fermion contact interactions at LC with polarization

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    Fermion compositeness, and other types of new physics that can be described by the exchange of very massive particles, can manifest themselves as the result of an effective four-fermion contact interaction. In the case of the processes e+eμ+μ,τ+τ,bˉbe^+e^-\to \mu^+\mu^-,\tau^+\tau^-,\bar{b}b and cˉc\bar{c}c at future e+ee^+e^- colliders with s=0.51\sqrt{s}=0.5-1 TeV, we examine the sensitivity to four-fermion contact interactions of two new integrated observables, σ+\sigma_+ and σ\sigma_-, conveniently defined for such kind of analysis. We find that, if longitudinal polarization of the electron beam were available, these observables would offer the opportunity to separate the helicity cross sections and, in this way, to derive model-independent bounds on the relevant parameters.Comment: 13 pages, LaTe

    Excitation model of cardiac p cells of the cardiac conduction system

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    The article considers elaboration of the mathematical model of cardiac electrical activity which will allow investigating excitation propagation processes at all sites of the cardiac conduction system. The proposed model is generated on the basis of parametric elements of an electric circuit with distributed parameters and approximation of time dependencies of conduction in ion channels by cubic splines

    Visualization of the heart with help of cardiographic equipment

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    This study presents the problems associated with cardiovascular diseases (CVD) and Twocomponent FitzHugh - Nagumo model and heart condition imaging algorithm are considered. Aspects of work aimed at designing and developing of the hardware and software complex based on the information obtained with the help of an electrocardiograph
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