Very-High-Energy Gamma-Ray Signal from Nuclear Photodisintegration as a Probe of Extragalactic Sources of Ultrahigh-Energy Nuclei

It is crucial to identify the ultrahigh-energy cosmic-ray (UHECR) sources and probe their unknown properties. Recent results from the Pierre Auger Observatory favor a heavy nuclear composition for the UHECRs. Under the requirement that heavy nuclei survive in these sources, using gamma-ray bursts as an example, we predict a diagnostic gamma-ray signal, unique to nuclei - the emission of de-excitation gamma rays following photodisintegration. These gamma rays, boosted from MeV to TeV-PeV energies, may be detectable by gamma-ray telescopes such as VERITAS, HESS, and MAGIC, and especially the next-generation CTA and AGIS. They are a promising messenger to identify and study individual UHE nuclei accelerators.Comment: 7 pages, 4 figures, accepted for publication in PRD, with extended descriptions. Conclusions unchange

Variational approach to the Hubbard model in a C60 cluster

5 págs.; 4 figs.; 3 tabs.We propose a computational scheme for the Hubbard model in the C60 cluster in which the interaction with the Fermi sea of charges added to the neutral molecule is switched on sequentially. This is applied to the calculation of the balance of charging energies, within a low-energy truncation of the space of states which produces moderate errors for an intermediate range of the interaction strength. ©1996 American Physical SocietyPeer Reviewe

Phase diagram of carbon nanotube ropes

14 págs.; 9 figs.; 1 tab. ; PACS number(s): 71.20.Tx, 71.10.Pm, 74.50.1rThe zero-temperature phase diagram of carbon nanotube ropes is studied using a computational framework that incorporates the renormalization of intratube interactions and the effect of intertube Coulomb screening. This allows us to undertake a systematic analysis as a function of the number of metallic nanotubes in the rope and the effective strength of the phonon-mediated interaction. We find that there is in general a weak-coupling regime of the interactions, corresponding to Luttinger-liquid behavior in thin ropes and to superconducting behavior in sufficiently thick ropes. Furthermore, we show the existence of exotic phases in the strong-coupling regime, characterized by the appearance of charge instabilities that depend on the helicity and the doping level of the nanotubes in the rope. Our approach allows for the simultaneous analysis of the scaling of the Cooper-pair tunneling amplitude between metallic nanotubes, making it possible to discern the crossover from purely one-dimensional physics to the setting of three-dimensional Cooper-pair coherence. We provide then good estimates of the superconducting transition temperature and discuss the connection of our results with recent experiments. ©2004 American Physical SocietyJ. V. A. acknowledges support from S. Moukouri and stimulating discussions with J. Allen. J. G. acknowledges financial support from the Ministerio de Ciencia y Tecnología Grant No. BFM2003-05317.Peer Reviewe

Large deviations for clocks of self-similar processes

The Lamperti correspondence gives a prominent role to two random time changes: the exponential functional of a L\'evy process drifting to $\infty$ and its inverse, the clock of the corresponding positive self-similar process. We describe here asymptotical properties of these clocks in large time, extending the results of Yor and Zani

Home Comforts during the Covid-19 Lockdown

This report summarises findings of a national survey of 2,500 households (representing 7,200 people) aimed at understanding how well or how poorly the design of our homes and their immediate neighbourhoods supported us during the period of coronavirus lockdown. The intention was to understand what we can learn from this period of unprecedented stress on our home environments. The findings offer insights into how we should be designing or adapting them in the future in order that they are more resilient and better able to support happy and healthy lifestyles

A Housing Design Audit for England

With the drive to deliver more homes across the country has come a loud call for those developments to be of a high standard of design in order to deliver high quality, liveable and sustainable environments for residents. Research has consistently shown that high quality design makes new residential developments more acceptable to local communities and delivers huge value to all. Housing design audits represent systematic approaches to assess the design quality of the external residential environment. This new audit evaluates the design of 142 large-scale housing-led development projects across England against seventeen design considerations. It provides enough data for comparisons to be made regionally and against the results of previous housing design audits conducted over a decade ago. It establishes a new baseline from which to measure progress on housing design quality in the future. Whilst some limited progress has been made in some regions, overwhelmingly the message is that the design of new housing environments in England are ‘mediocre’ or ‘poor’. Collectively, we need to significantly raise our game if we are to create the sorts of places that future generations will feel proud to call home

Quality Evaluation of Parmigiano Reggiano Cheese by a Novel Nanowire Device S3 and Evaluation of the VOCs Profile

Abstract A novel nanowire-based sensor device is presented for the quality evaluation of the Italian Parmigiano Reggiano (PR) cheese. As a Protected Designation of Origin (PDO) trademark product, the cheese should follow stringent manufacturing guidelines and must exhibit the representative aromatic volatile organic compounds (VOCs) biomarkers and sensory profile. Any alteration in these features indicates an adulteration of the product as many low quality and substandard PR cheeses are widely available in the market. Different types of grated cheese samples were analyzed and the VOCs were characterized by evaluating the samples with the portable sensor device S3 and Gas Chromatography–Mass Spectrometry technique. The ability of S3 device to distinguish the cheese quality demonstrates its suitability for monitoring the quality control and authenticity of PR cheese

Price of Anarchy for Mean Field Games

The price of anarchy, originally introduced to quantify the inefficiency of selfish behavior in routing games, is extended to mean field games. The price of anarchy is defined as the ratio of a worst case social cost computed for a mean field game equilibrium to the optimal social cost as computed by a central planner. We illustrate properties of such a price of anarchy on linear quadratic extended mean field games, for which explicit computations are possible. Various asymptotic behaviors of the price of anarchy are proved for limiting behaviors of the coefficients in the model and numerics are presented.Comment: 38 pages, 10 plot