Short periodic orbits theory for partially open quantum maps

We extend the semiclassical theory of short periodic orbits [Phys. Rev. E {\bf 80}, 035202(R) (2009)] to partially open quantum maps. They correspond to classical maps where the trajectories are partially bounced back due to a finite reflectivity $R$. These maps are representative of a class that has many experimental applications. The open scar functions are conveniently redefined, providing a suitable tool for the investigation of these kind of systems. Our theory is applied to the paradigmatic partially open tribaker map. We find that the set of periodic orbits that belong to the classical repeller of the open map ($R=0$) are able to support the set of long-lived resonances of the partially open quantum map in a perturbative regime. By including the most relevant trajectories outside of this set, the validity of the approximation is extended to a broad range of $R$ values. Finally, we identify the details of the transition from qualitatively open to qualitatively closed behaviour, providing an explanation in terms of short periodic orbits.Comment: 6 pages, 4 figure

State and Institutional Policies on In-State Resident Tuition and Financial Aid for Undocumented Students: Examining Constraints and Opportunities

In this article, we examine policies related to in-state resident tuition and state financial aid policies aimed at undocumented students. To help frame the discussion and spark further debate and research in this area the article seeks to do three things. First, it provides a comprehensive review of state and institutional in-state tuition policies aimed at undocumented students as well as state college or university system responses. Second, it charts the policy landscape for state financial aid access for this population. Third, it examines the numerous implications that such policies engender and highlights the role of the federal government and the proposed Dream Act in mitigating some of these concerns. It closes by underscoring the important financial role played by the critical interaction of state, institutional, and federal policies in making college going a reality for these students while proposing avenues for future study around the issue

The role of short periodic orbits in quantum maps with continuous openings

We apply a recently developed semiclassical theory of short periodic orbits to the continuously open quantum tribaker map. In this paradigmatic system the trajectories are partially bounced back according to continuous reflectivity functions. This is relevant in many situations that include optical microresonators and more complicated boundary conditions. In a perturbative regime, the shortest periodic orbits belonging to the classical repeller of the open map - a cantor set given by a region of exactly zero reflectivity - prove to be extremely robust in supporting a set of long-lived resonances of the continuously open quantum maps. Moreover, for step like functions a significant reduction in the number needed is obtained, similarly to the completely open situation. This happens despite a strong change in the spectral properties when compared to the discontinuous reflectivity case.Comment: 6 pages, 4 figures. arXiv admin note: text overlap with arXiv:1604.0181

Tolman mass, generalized surface gravity, and entropy bounds

In any static spacetime the quasi-local Tolman mass contained within a volume can be reduced to a Gauss-like surface integral involving the flux of a suitably defined generalized surface gravity. By introducing some basic thermodynamics and invoking the Unruh effect one can then develop elementary bounds on the quasi-local entropy that are very similar in spirit to the holographic bound, and closely related to entanglement entropy.Comment: V1: 4 pages. Uses revtex4-1; V2: Three references added; V3: Some notational changes for clarity; introductory paragraph rewritten; no physics changes. This version accepted for publication in Physical Review Letter

Sensitivity to Timing and Order in Human Visual Cortex

Visual recognition takes a small fraction of a second and relies on the cascade of signals along the ventral visual stream. Given the rapid path through multiple processing steps between photoreceptors and higher visual areas, information must progress from stage to stage very quickly. This rapid progression of information suggests that fine temporal details of the neural response may be important to the how the brain encodes visual signals. We investigated how changes in the relative timing of incoming visual stimulation affect the representation of object information by recording intracranial field potentials along the human ventral visual stream while subjects recognized objects whose parts were presented with varying asynchrony. Visual responses along the ventral stream were sensitive to timing differences between parts as small as 17 ms. In particular, there was a strong dependency on the temporal order of stimulus presentation, even at short asynchronies. This sensitivity to the order of stimulus presentation provides evidence that the brain may use differences in relative timing as a means of representing information.Comment: 10 figures, 1 tabl

Charge order induced by electron-lattice interaction in NaV2O5

We present Density Matrix Renormalization Group calculations of the ground-state properties of quarter-filled ladders including static electron-lattice coupling. Isolated ladders and two coupled ladders are considered, with model parameters obtained from band-structure calculations for $\alpha^\prime$-NaV$_2$O$_5$. The relevant Holstein coupling to the lattice causes static out-of-plane lattice distortions, which appear concurrently with a charge-ordered state and which exhibit the same zigzag pattern observed in experiments. The inclusion of electron-lattice coupling drastically reduces the critical nearest-neighbor Coulomb repulsion $V_c$ needed to obtain the charge-ordered state. No spin gap is present in the ordered phase. The charge ordering is driven by the Coulomb repulsion and the electron-lattice interaction. With electron-lattice interaction, coupling two ladders has virtually no effect on $V_c$ or on the characteristics of the charge-ordered phase. At V=0.46\eV, a value consistent with previous estimates, the lattice distortion, charge gap, charge order parameter, and the effective spin coupling are in good agreement with experimental data for NaV$_2$O_5$.Comment: 7 pages, 9 figure

Volatility Surface and Skewness in Live Cattle Futures Price Distributions with Application to North American BSE Announcements

options markets, live cattle, volatility, pricing density function, Financial Economics, Livestock Production/Industries, Risk and Uncertainty,

On the tensor convolution and the quantum separability problem

We consider the problem of separability: decide whether a Hermitian operator on a finite dimensional Hilbert tensor product is separable or entangled. We show that the tensor convolution defined for certain mappings on an almost arbitrary locally compact abelian group, give rise to formulation of an equivalent problem to the separability one.Comment: 13 pages, two sections adde

Social Enterprise Investment Fund evaluation - phase one: scoping, review and methodology development.

The £100m Social Enterprise Investment Fund (SEIF) aims to stimulate and increase the numbers of Social Enterprises (SEs) that are involved in the delivery of health and social care services via grants, loans and equity investments. The SEIF seeks to generate sufficient returns on its investments to become self-sustaining over the initial fund period (2007-2011). The evaluation of the SEIF aims to: - assess the effectiveness of the Fund in supporting SEs; - identify the impact of the SEIF including some evidence of the types of social benefits produced through the activities of SEs; and - identify lessons and make recommendations for the future improvement of the SEIF and the role of SEs in the delivery of health and social care services. The objectives of this component of the research have been to: - explore stakeholder expectations for SEIF and establish a common view of how the success of SEIF should be measured, and the mechanisms through which the SEIF is expected to achieve its outcomes; - refine the study design in the light of the programme theories which have surfaced

Distinguished bases of exceptional modules

Exceptional modules are tree modules. A tree module usually has many tree bases and the corresponding coefficient quivers may look quite differently. The aim of this note is to introduce a class of exceptional modules which have a distinguished tree basis, we call them radiation modules (generalizing an inductive construction considered already by Kinser). For a Dynkin quiver, nearly all indecomposable representations turn out to be radiation modules, the only exception is the maximal indecomposable module in case E_8. Also, the exceptional representation of the generalized Kronecker quivers are given by radiation modules. Consequently, with the help of Schofield induction one can display all the exceptional modules of an arbitrary quiver in a nice way.Comment: This is a revised and slightly expanded version. Propositions 1 and 2 have been corrected, some examples have been inserte