Nonclassical Particle Transport in 1-D Random Periodic Media

We investigate the accuracy of the recently proposed nonclassical transport equation. This equation contains an extra independent variable compared to the classical transport equation (the path-length $s$), and models particle transport taking place in homogenized random media in which a particle's distance-to-collision is not exponentially distributed. To solve the nonclassical equation one needs to know the $s$-dependent ensemble-averaged total cross section, $\Sigma_t(\mu,s)$, or its corresponding path-length distribution function, $p(\mu,s)$. We consider a 1-D spatially periodic system consisting of alternating solid and void layers, randomly placed in the $x$-axis. We obtain an analytical expression for $p(\mu,s)$ and use this result to compute the corresponding $\Sigma_t(\mu,s)$. Then, we proceed to numerically solve the nonclassical equation for different test problems in rod geometry; that is, particles can move only in the directions $\mu=\pm 1$. To assess the accuracy of these solutions, we produce "benchmark" results obtained by (i) generating a large number of physical realizations of the system, (ii) numerically solving the transport equation in each realization, and (iii) ensemble-averaging the solutions over all physical realizations. We show that the numerical results validate the nonclassical model; the solutions obtained with the nonclassical equation accurately estimate the ensemble-averaged scalar flux in this 1-D random periodic system, greatly outperforming the widely-used atomic mix model in most problems.Comment: 50 pages; 7 Tables; 21 Figures. This is an expanded version (full journal article) of the conference paper listed in arXiv:1412.338

The spatial coherence of weakly interacting one-dimensional non-equilibrium Bosonic quantum fluids

We present a theoretical analysis of spatial correlations in a one-dimensional driven-dissipative non-equilibrium condensate. Starting from a stochastic generalized Gross-Pitaevskii equation, we derive a noisy Kuramoto-Sivashinsky equation for the phase dynamics. For sufficiently strong interactions, the coherence decays exponentially in close analogy to the equilibrium Bose gas. When interactions are small on a scale set by the nonequilibrium condition, we find through numerical simulations a crossover between a Gaussian and exponential decay with peculiar scaling of the coherence length on the fluid density and noise strength.Comment: 5 pages, 2 figures, supplemental materia

J/psi (psi') production at the Tevatron and LHC at O(\alpha_s^4v^4) in nonrelativistic QCD

We present a complete evaluation for \jpsi(\psip) prompt production at the Tevatron and LHC at next-to-leading order in nonrelativistic QCD, including color-singlet, color-octet, and higher charmonia feeddown contributions. The short-distance coefficients of \pj at next-to-leading order are found to be larger than leading order by more than an order of magnitude but with a minus sign at high transverse momentum $p_T$. Two new linear combinations of color-octet matrix elements are obtained from the CDF data, and used to predict \jpsi production at the LHC, which agrees with the CMS data. The possibility of \sa dominance and the \jpsi polarization puzzle are also discussed.Comment: Version published in PRL, 4 pages, 4 figure

Enhanced visibility of graphene: effect of one-dimensional photonic crystal

We investigate theoretically the light reflectance of a graphene layer prepared on the top of one-dimensional Si/SiO2 photonic crystal (1DPC). It is shown that the visibility of the graphene layers is enhanced greatly when 1DPC is added, and the visibility can be tuned by changing the incident angle and light wavelengths. This phenomenon is caused by the absorption of the graphene layer and the enhanced reflectance of the 1DPC.Comment: 4 pages, 4 figures. published, ApplPhysLett_91_18190

Macroscopic quantum computation using Bose-Einstein condensates

Quantum computation using qubits made of two component Bose-Einstein condensates (BECs) is analysed. The use of BECs allows for an increase of energy scales via bosonic enhancement, resulting in gate operations that can be performed at a macroscopically large energy scale. The large energy scale of the gate operations results in quantum algorithms that may be executed at a time reduced by a factor of N, where N is the number of bosons per qubit. The encoding of the qubits allows for no intrinsic penalty on decoherence times. We illustrate the scheme by an application to Deutsch's and Grover's algorithms.Comment: 10 pages, 3 figure

Bridging the gap by shaking superfluid matter

In cold compact stars, Cooper pairing between fermions in dense matter leads to the formation of a gap in their excitation spectrum and typically exponentially suppresses transport properties. However, we show here that weak Urca reactions become strongly enhanced and approach their ungapped level when the star undergoes density oscillations of sufficiently large amplitude. We study both the neutrino emissivity and the bulk viscosity due to direct Urca processes in hadronic, hyperonic and quark matter and discuss different superfluid and superconducting pairing patterns.Comment: 5 pages, 4 figure

Barriers to Financial Compensation for Artists in the Recording Industry in the Digital Age

For decades, consumers, due to frequent technological advances, have utilized a variety of music-listening processes that have each become obsolete as more easily accessible technologies emerged. This change in music consumption methods is often detrimental to parties in the recording industry. The digitalization of the recording industry has allowed consumers to obtain music through means other than physical purchase, leading to well-documented financial insecurity for artists (Eiriz & Leite, 2017). In 2018, the Music Industry Research Association (MIRA) conducted a survey of 1,227 musicians and found that 61% of the group agreed that their music-related income is not enough to cover their living expenses (MIRA, 2018). For this reason, frequent attempts to deter widespread copyright infringement have been made. However, the aggressive litigation strategy of the recording industry and the development of streaming services as a viable music consumption method have instead decreased sales and negatively impacted artists’ revenue from the recording industry (Fedock, 2005; Marshall, 2015)

The Path Along the Ridge: Regional Planning in the Face of Uncertainty

The Northwest Power Act responds to the changing circumstances of electric power in the Pacific Northwest by defining policy directions and creating new institutional arrangements for regional power planning. The Northwest Power Planning Council (Council) is the agent of the region in meeting the challenges of planning under the Act. This paper discusses the conceptual framework of regional power planning—a task that confronts a degree of uncertainty and risk without historical precedent