Absolute convergence of the twisted Arthur-Selberg trace formula

We show that the distributions occurring in the geometric and spectral side of the twisted Arthur-Selberg trace formula extend to non-compactly supported test functions. The geometric assertion is modulo a hypothesis on root systems proven when the group is split. The result extends the work of Finis-Lapid (and M\"uller, spectral side) to the twisted setting. We use the absolute convergence to give a geometric interpretation of sums of residues of certain Rankin-Selberg L-functions.Comment: Accepted to be published in Mathematische Zeitschrift. Removed proof of RCL for base change; Section 8 now requires Assumption 8.1. Also, minor correction

An exactly solvable many-body problem in one dimension

For N impenetrable particles in one dimension where only the nearest and next-to-nearest neighbours interact, we obtain the complete spectrum both on a line and on a circle. Further, we establish a mapping between these N-body problems and the short-range Dyson model introduced recently to model intermediate spectral statistics in some systems using which we compute the two-point correlation function and prove the absence of long-range order in the corresponding many-body theory. Further, we also show the absence of off-diagonal long-range order in these systems.Comment: LaTeX, 4 pages, 1 figur

Origin of Matching Effect in Anti-dot Array of Superconducting NbN Thin Films

We investigate the origin of matching effect observed in disordered superconducting NbN thin films with periodic array of holes. In addition to the periodic variation in the electrical resistance just above the superconducting transition temperature, Tc0, we find pronounced periodic variations with magnetic field in all dynamical quantities which can be influenced by flux-line motion under an external drive such as the magnetic shielding response and the critical current which survive in some samples down to temperatures as low as 0.09Tc0. In contrast, the superconducting energy gap, D which is a true thermodynamic quantity does not show any periodic variation with magnetic fields for the same films. Our results show that commensurate pinning of the flux line lattice driven by vortex-vortex interaction is the dominant mechanism for the observed matching effects in these superconducting anti-dot films rather than Little-Parks like quantum interference effect.Comment: 18 pages, 6 figure

Tavola distribuzione normale

3-Methyltetrahydrofuran (3-MTHF) is proposed to be a promising fuel component among the cyclic oxygenated species. To have detailed insight of its combustion kinetics, intramolecular hydrogen shift reactions for the ROO to QOOH reaction class are studied for eight ROO isomers of 3-MTHF. Rate constants of all possible reaction paths that involve formation of cyclic transition states are computed by employing the CBS-QB3 composite method. A Pitzer–Gwinn-like approximation has been applied for the internal rotations in reactants, products, and transition states for the accurate treatment of hindered rotors. Calculated relative barrier heights highlight that the most favorable reaction channel proceeds via a six membered transition state, which is consistent with the computed rate constants. Comparing total rate constants in ROO isomers of 3-MTHF with the corresponding isomers of methylcyclopentane depicts faster kinetics in 3-MTHF than methylcyclopentane reflecting the effect of ring oxygen on the intramolecular hydrogen shift reactions

Random on-board pixel sampling (ROPS) X-ray Camera

Recent advances in compressed sensing theory and algorithms offer new possibilities for high-speed X-ray camera design. In many CMOS cameras, each pixel has an independent on-board circuit that includes an amplifier, noise rejection, signal shaper, an analog-to-digital converter (ADC), and optional in-pixel storage. When X-ray images are sparse, i.e., when one of the following cases is true: (a.) The number of pixels with true X-ray hits is much smaller than the total number of pixels; (b.) The X-ray information is redundant; or (c.) Some prior knowledge about the X-ray images exists, sparse sampling may be allowed. Here we first illustrate the feasibility of random on-board pixel sampling (ROPS) using an existing set of X-ray images, followed by a discussion about signal to noise as a function of pixel size. Next, we describe a possible circuit architecture to achieve random pixel access and in-pixel storage. The combination of a multilayer architecture, sparse on-chip sampling, and computational image techniques, is expected to facilitate the development and applications of high-speed X-ray camera technology.Comment: 9 pages, 6 figures, Presented in 19th iWoRI

Intermediate statistics for a system with symplectic symmetry: the Dirac rose graph

We study the spectral statistics of the Dirac operator on a rose-shaped graph---a graph with a single vertex and all bonds connected at both ends to the vertex. We formulate a secular equation that generically determines the eigenvalues of the Dirac rose graph, which is seen to generalise the secular equation for a star graph with Neumann boundary conditions. We derive approximations to the spectral pair correlation function at large and small values of spectral spacings, in the limit as the number of bonds approaches infinity, and compare these predictions with results of numerical calculations. Our results represent the first example of intermediate statistics from the symplectic symmetry class.Comment: 26 pages, references adde

The acceptability, feasibility and impact of a lay health counsellor delivered health promoting schools programme in India: a case study evaluation.

BACKGROUND: Studies in resource-limited settings have shown that there are constraints to the use of teachers, peers or health professionals to deliver school health promotion interventions. School health programmes delivered by trained lay health counsellors could offer a cost-effective alternative. This paper presents a case study of a multi-component school health promotion intervention in India that was delivered by lay school health counsellors, who possessed neither formal educational nor health provider qualifications. METHODS: The intervention was based on the WHO's Health Promoting Schools framework, and included health screening camps; an anonymous letter box for student questions and complaints; classroom-based life skills training; and, individual psycho-social and academic counselling for students. The intervention was delivered by a lay school health counsellor who had attained a minimum of a high school education. The counsellor was trained over four weeks and received structured supervision from health professionals working for the implementing NGO. The evaluation design was a mixed methods case study. Quantitative process indicators were collected to assess the extent to which the programme was delivered as planned (feasibility), the uptake of services (acceptability), and the number of students who received corrective health treatment (evidence of impact). Semi-structured interviews were conducted over two years with 108 stakeholders, and were analysed to identify barriers and facilitators for the programme (feasibility), evaluate acceptability, and gather evidence of positive or negative effects of the programme. RESULTS: Feasibility was established by the high reported coverage of all the targeted activities by the school health counsellor. Acceptability was indicated by a growing number of submissions to the students' anonymous letter-box; more students self-referring for counselling services over time; and, the perceived need for the programme, as expressed by principals, parents and students. A minority of teachers complained that there was inadequate information sharing about the programme and mentioned reservations about the capacities of the lay health counsellor. Preliminary evidence of the positive effects of the programme included the correction of vision problems detected in health screening camps, and qualitative evidence of changes in health-related knowledge and behaviour of students. CONCLUSION: A task-shifting approach of delegating school health promotion activities to lay school health counsellors rather than education or health professionals shows promise of effectiveness as a scalable model for promoting the health and well being of school based adolescents in resource constrained settings