Dark Matter in Universal Extra Dimension Models: γKK\gamma_{KK} vrs νR,KK\nu_{R,KK}

We show that in a class of universal extra dimension models (UED), which solves both the neutrino mass and proton decay problem, an admixture of KK photon and KK right handed neutrinos can provide the required amount of cold dark matter (CDM). This model has two parameters $R^{-1}$ and $M_{Z'}$ ($R$ is the radius of the extra space dimensions and $Z'$ the extra neutral gauge boson of the model). Using the value of the relic CDM density, combined with the results from the cryogenic searches for CDM, we obtain upper limits on $R^{-1}$ of about 400-650 GeV and $M_{Z'}\leq 1.5$ TeV, both being accessible to LHC. In some regions of the parameter space, the dark matter-nucleon scattering cross section can be as high as of $10^{-44}$ cm$^2$, which can be probed by the next round of dark matter search experiments.Comment: 13 pages, 2 figures; minor changes; to appear in Phys. Rev.

Publicness, Privacy and Confidentiality in the Single-Serving Quantum Broadcast Channel

The 2-receiver broadcast channel is studied: a network with three parties where the transmitter and one of the receivers are the primarily involved parties and the other receiver considered as third party. The messages that are determined to be communicated are classified into public, private and confidential based on the information they convey. The public message contains information intended for both parties and is required to be decoded correctly by both of them, the private message is intended for the primary party only, however, there is no secrecy requirement imposed upon it meaning that it can possibly be exposed to the third party and finally the confidential message containing information intended exclusively for the primary party such that this information must be kept completely secret from the other receiver. A trade-off arises between the rates of the three messages, when one of the rates is high, the other rates may need to be reduced to guarantee the reliable transmission of all three messages. The encoder performs the necessary equivocation by virtue of dummy random numbers whose rate is assumed to be limited and should be considered in the trade-off as well. We study this trade-off in the one-shot regime of a quantum broadcast channel by providing achievability and (weak) converse regions. In the achievability, we prove and use a conditional version of the convex-split lemma as well as position-based decoding. By studying the asymptotic behaviour of our bounds, we will recover several well-known asymptotic results in the literature.Comment: 23 pages, 1 figure, journa

Juries and Justice: Are Malpractice and Other Personal Injuries Created Equal?

A study analyzed the civil jury system and the difference in personal injury awards between automobile and deep-pocket defendants, especially in medical malpractice cases. Six conclusions were reached, including the finding that juries sometimes respond emotionally and award some objectively similar cases higher damages than others

Investigation of nonlinear interaction phenomena in the ionosphere

Ionospheric phenomena as thermal radiation noise, propagation of naturally occurring radio noise through ionosphere, and generation of very low frequency emission

Albedos of Main-Belt Comets 133P/Elst-Pizarro and 176P/LINEAR

We present the determination of the geometric R-band albedos of two main-belt comet nuclei based on data from the Spitzer Space Telescope and a number of ground-based optical facilities. For 133P/Elst-Pizarro, we find an albedo of p_R=0.05+/-0.02 and an effective radius of r_e=1.9+/-0.3 km (estimated semi-axes of a~2.3 km and b~1.6 km). For 176P/LINEAR, we find an albedo of p_R=0.06+/-0.02 and an effective radius of r_e=2.0+/-0.2 km (estimated semi-axes of a~2.6 km and b~1.5 km). In terms of albedo, 133P and 176P are similar to each other and are typical of other Themis family asteroids, C-class asteroids, and other comet nuclei. We find no indication that 133P and 176P are compositionally unique among other dynamically-similar (but inactive) members of the Themis family, in agreement with previous assertions that the two objects most likely formed in-situ. We also note that low albedo (p_R<0.075) remains a consistent feature of all cometary (i.e., icy) bodies, whether they originate in the inner solar system (the main-belt comets) or in the outer solar system (all other comets).Comment: 11 pages, 3 figures, accepted for publication in ApJ