Dynamical Dark Matter from Strongly-Coupled Dark Sectors

Dynamical Dark Matter (DDM) is an alternative framework for dark-matter physics in which the dark sector comprises a vast ensemble of particle species whose decay widths are balanced against their cosmological abundances. Previous studies of this framework have focused on a particular class of DDM ensembles --- motivated primarily by KK towers in theories with extra dimensions --- in which the density of states scales roughly as a polynomial of mass. In this paper, by contrast, we study the properties of a different class of DDM ensembles in which the density of states grows exponentially with mass. Ensembles with this Hagedorn-like property arise naturally as the "hadrons" associated with the confining phase of a strongly-coupled dark sector; they also arise naturally as the gauge-neutral bulk states of Type I string theories. We study the dynamical properties of such ensembles, and demonstrate that an appropriate DDM-like balancing between decay widths and abundances can emerge naturally --- even with an exponentially rising density of states. We also study the effective equations of state for such ensembles, and investigate some of the model-independent observational constraints on such ensembles that follow directly from these equations of state. In general, we find that such constraints tend to introduce correlations between various properties of these DDM ensembles such as their associated mass scales, lifetimes, and abundance distributions. For example, we find that these constraints allow DDM ensembles with energy scales ranging from the GeV scale all the way to the Planck scale, but the total present-day cosmological abundance of the dark sector must be spread across an increasing number of different states in the ensemble as these energy scales are dialed from the Planck scale down to the GeV scale. Numerous other correlations and constraints are also discussed.Comment: 29 pages, LaTeX, 10 figure

Cryptanalysis of a multi-party quantum key agreement protocol with single particles

Recently, Sun et al. [Quant Inf Proc DOI: 10.1007/s11128-013-0569-x] presented an efficient multi-party quantum key agreement (QKA) protocol by employing single particles and unitary operations. The aim of this protocol is to fairly and securely negotiate a secret session key among $N$ parties with a high qubit efficiency. In addition, the authors claimed that no participant can learn anything more than his/her prescribed output in this protocol, i.e., the sub-secret keys of the participants can be kept secret during the protocol. However, here we points out that the sub-secret of a participant in Sun et al.'s protocol can be eavesdropped by the two participants next to him/her. In addition, a certain number of dishonest participants can fully determine the final shared key in this protocol. Finally, we discuss the factors that should be considered when designing a really fair and secure QKA protocol.Comment: 7 page

Study of Teaching Model based on Cooperative Learning

Cooperative learning is a popular teaching method now in the world. This paper first discusses the teaching model based on cooperative learning, then analyzes the advantages of cooperative learning and at last proposes the steps of carrying out cooperative learning. It is necessary to introduce the teaching model based on cooperative learning into the teaching for training software talents of China.Key words: Cooperative Learning; Training Model; Teaching Refor

Long-rang Correlation for USD/EUR based on Semi-parametric Estimation

This paper chooses closing price return rate series of EUR/USD to study. Sample interval covers from 22th July 2005 to 15th Sep 2008(before the financial crisis) and from 16th September 2008 to 19th May 2010(after the financial crisis).The author put forward semi-parameter estimation methods (Standard GPH Method, Tapered GPH Method), and concluded through comparable analysis that: In the conditions of V using T0.5、T0.525、T0.55、T0.575、T0.6 samples, standard GPH and tapered GPH tests are adopted. The results show that Fractal dimension parameter d is significantly greater than 0 and the statistics are more than critical value of 1% level before financial crisis both EUR/USD. After financial crisis, the parameter has become smaller than that before financial crisis, which is near 0 significantly. In the long term, there is no trend or structural breaks in the exchange market. This study's conclusion was that long-term memory exists in daily return time series of EUR/USD become smaller after financial crisis. Key words: EUR/USD; semi-parameter estimation methods; financial crisi

Up-regulation of corticotropin releasing hormone is associated with the downregulation of corticotropin releasing hormone binding protein and up-regulation of IL- 33 and IL-8 expression in psoriasis

Purpose: To determine the expression of corticotropin releasing hormone (CRH) in psoriasis and normal skin biopsy samples, and to correlate the expression of CRH with the expression of CRHBP and inflammatory cytokines IL-8 and IL-33.Methods: Psoriasis and normal skin biopsy samples were obtained from three psoriatic and three normal healthy patients. The mRNA expression was examined by quantitative real-time polymerase chain reaction (RT-PCR). Protein expression analysis was carried out by Western blotting and then further validated by immunohistochemistry.Results: The results of the present study revealed that the expression of CRH was highly significant (p < 0.0001) in psoriatic skin, compared to normal skin. Increase of CRH in psoriatic samples ranged from 2.7 to 3.5-fold. Expression of CRH was associated with the concomitant downregulation of CRHBP in all the psoriatic skin biopsy samples, with expression of CRHBP 3.0 to 6.2-fold lower in psoriatic skin than in normal skin. Analysis of mRNA expression of IL-8 and IL-33, revealed that expression of both IL-8 and IL-33 was significantly (p < 0.0001) upregulated in psoriatic skin samples while the expression of IL-8 and IL-33 was approximately 4.1- and 3.2-fold higher in psoriatic skin than in normal skin. The expression of CRHBP, IL-8 and IL-33 was further confirmed by western blotting and immunohistochemistry results.Conclusion: The results confirm that the expression of CRH is associated with the suppression of CRHBP and upregulation of IL-8 and IL-33.Keywords: Psoriasis, Corticotropin releasing hormone, Inflammatory cytokines, Interleukin, Skin biops

Deciphering the Archaeological Record: Cosmological Imprints of Non-Minimal Dark Sectors

Many proposals for physics beyond the Standard Model give rise to a dark sector containing many degrees of freedom. In this work, we explore the cosmological implications of the non-trivial dynamics which may arise within such dark sectors, focusing on decay processes which take place entirely among the dark constituents. First, we demonstrate that such decays can leave dramatic imprints on the resulting dark-matter phase-space distribution. In particular, this distribution need not be thermal -- it can even be multi-modal, exhibiting a non-trivial pattern of peaks and troughs as a function of momentum. We then proceed to show how these features can induce modifications to the matter power spectrum. Finally, we assess the extent to which one can approach the archaeological "inverse" problem of deciphering the properties of an underlying dark sector from the matter power spectrum. Indeed, one of the main results of this paper is a remarkably simple conjectured analytic expression which permits the reconstruction of many of the important features of the dark-matter phase-space distribution directly from the matter power spectrum. Our results therefore provide an interesting toolbox of methods for learning about, and potentially constraining, the features of non-minimal dark sectors and their dynamics in the early universe.Comment: 55 pages, LaTeX, 21 figures, 4 table

A similarity metric for the inputs of OO programs and its application in adaptive random testing

Random testing (RT) has been identified as one of the most popular testing techniques, due to its simplicity and ease of automation. Adaptive random testing (ART) has been proposed as an enhancement to RT, improving its fault-detection effectiveness by evenly spreading random test inputs across the input domain. To achieve the even spreading, ART makes use of distance measurements between consecutive inputs. However, due to the nature of object-oriented software (OOS), its distance measurement can be particularly challenging: Each input may involve multiple classes, and interaction of objects through method invocations. Two previous studies have reported on how to test OOS at a single-class level using ART. In this study, we propose a new similarity metric to enable multiclass level testing using ART. When generating test inputs (for multiple classes, a series of objects, and a sequence of method invocations), we use the similarity metric to calculate the distance between two series of objects, and between two sequences of method invocations. We integrate this metric with ART and apply it to a set of open-source OO programs, with the empirical results showing that our approach outperforms other RT and ART approaches in OOS testing