Six Flavor Quark Matter

Macroscopic nuggets of quark matter were proposed several decades ago as a candidate for dark matter. The formation of these objects in the early universe requires the QCD phase transition to be first order - a requirement that is not satisfied in the Standard Model where lattice simulations reveal a continuous crossover instead. In this article we point out that new physics may supercool the electroweak phase transition to below the QCD scale, and the QCD phase transition with six massless quarks becomes first-order. As a result, the quark nuggets composed of six-flavor quark matter (6FQM) may survive as a viable dark matter candidate. The size of a 6FQM nugget is estimated to be around $10^{10}$ grams in mass and $10^{-2}$ cm in radius. The calculated relic abundance of 6FQM nuggets is comparable to the observed dark matter energy density; therefore, this scenario provides a compelling explanation for the coincident energy densities of dark and baryonic matter. We have explored various potential signatures - including a gravitational wave background, gravitational lensing, and transient photon emission from collisions with compact stars and other nuggets - and demonstrated that the favored region of parameter space is still allowed by current constraints while discovery of 6FQM nugget dark matter may require new experimental probes.Comment: 28+8 pages, 8 figures; v2 -- corrected a factor of 8 error in Eq. (3.15) and updated Fig. 5 accordingly. Conclusions remain unchange

RFID Based Navigation

The RFID (Radio Frequency Identification) based Navigation System is built and designed to allow both commercial and recreational drivers to know and monitor traffic patterns while on the road. By using the RFID based Navigation System, drivers will receive real time data to aid navigation which is a major benefit especially in an emergency situation. Further studies of the RFID technology will potentially open doors to the development of autonomous vehicles. The RFID based Navigation application is available for Android devices, and it presents drivers with real time, current data to aid navigation across a terrain in the shortest possible route. The server/database coordinates information exchange from vehicles to drivers. This is shown on the web based and mobile application. The RFID Reader uses the received RFID tag data to determine specific locations, directions, time, and the speed of the vehicle. Our team went on to divide the system design into three categories: the Android system application, the server/database, and the RFID Reader connection. For the purposes of our project, we used an RC car to test the navigation system. Our team used 50 RFID tags, and we were able to accomplish our goal of presenting navigation data in real time. While our results proved that the system is accurate in real time, covering all roadways will require a large amount of tags leading to time related issues.https://scholarscompass.vcu.edu/capstone/1099/thumbnail.jp

Electronic Channels of Distribution: Challenges and Solutions for Hotel Operators

This paper addresses the issues of hotel operators identifying effective means of allocating rooms through various electronic channels of distribution. Relying upon the theory of coercive isomorphism, a think tank was constructed to identify and define electronic channels of distribution currently being utilized in the hotel industry. Through two full-day focus groups consisting of key hotel executives and industry practitioners, distribution channels were identified as were challenges and solutions associated with each

The Dirichlet Markov Ensemble

We equip the polytope of $n\times n$ Markov matrices with the normalized trace of the Lebesgue measure of $\mathbb{R}^{n^2}$. This probability space provides random Markov matrices, with i.i.d. rows following the Dirichlet distribution of mean $(1/n,...,1/n)$. We show that if \bM is such a random matrix, then the empirical distribution built from the singular values of\sqrt{n} \bM tends as $n\to\infty$ to a Wigner quarter--circle distribution. Some computer simulations reveal striking asymptotic spectral properties of such random matrices, still waiting for a rigorous mathematical analysis. In particular, we believe that with probability one, the empirical distribution of the complex spectrum of \sqrt{n} \bM tends as $n\to\infty$ to the uniform distribution on the unit disc of the complex plane, and that moreover, the spectral gap of \bM is of order $1-1/\sqrt{n}$ when $n$ is large.Comment: Improved version. Accepted for publication in JMV