Isotope shift on the chlorine electron affinity revisited by an MCHF/CI approach

Today, the electron affinity is experimentally well known for most of the elements and is a useful guideline for developing ab initio computational methods. However, the measurements of isotope shifts on the electron affinity are limited by both resolution and sensitivity. In this context, theory eventually contributes to the knowledge and understanding of atomic structures, even though correlation plays a dominant role in negative ions properties and, particularly, in the calculation of the specific mass shift contribution. The present study solves the longstanding discrepancy between calculated and measured specific mass shifts on the electron affinity of chlorine (Phys. Rev. A 51 (1995) 231)Comment: 18 pages, 2 figures, 7 table

Polynomiality for Bin Packing with a Constant Number of Item Types

We consider the bin packing problem with d different item sizes s_i and item multiplicities a_i, where all numbers are given in binary encoding. This problem formulation is also known as the 1-dimensional cutting stock problem. In this work, we provide an algorithm which, for constant d, solves bin packing in polynomial time. This was an open problem for all d >= 3. In fact, for constant d our algorithm solves the following problem in polynomial time: given two d-dimensional polytopes P and Q, find the smallest number of integer points in P whose sum lies in Q. Our approach also applies to high multiplicity scheduling problems in which the number of copies of each job type is given in binary encoding and each type comes with certain parameters such as release dates, processing times and deadlines. We show that a variety of high multiplicity scheduling problems can be solved in polynomial time if the number of job types is constant

Sickness and injury leave in France: moral hazard or strain?

From 1997 to 2001, the total payment to compensate for sickness and injury leaves increased dramatically in France. Since this change coincided with a decrease in unemployment rate,three hypothesizes should be proposed as possible explanations consistently with the literature: moral hazard (workers fear less to loose their job, therefore use sickness leave more confidently); strain (workers work longer hours or under more stringent rules); labor-force composition effect (less healthy individuals are incorporated into the labor force). We investigate the first two strands of explanation using a household survey (ESPS) enriched with claims data from compulsory health insurance funds on sickness leaves (EPAS). We model separately number of leaves per individual (cumulative logit) and duration of leaves (random-effect model). According to our findings, in France, the individual propensity to take sickness leave is mainly influenced by strain in the workplace and by a labor-force composition effect. Conditional duration of spells is not well explained at the individual level: the only significant factor is usual weekly work duration. Influence of moral hazard is not clearly ascertained: it has few impact on occurrences of leave and no impact on duration.Sickness, Labour Force

Global well-posedness of a conservative relaxed cross diffusion system

We prove global existence in time of solutions to relaxed conservative cross diffusion systems governed by nonlinear operators of the form $u_i\to \partial_tu_i-\Delta(a_i(\tilde{u})u_i)$ where the $u_i, i=1,...,I$ represent $I$ density-functions, $\tilde{u}$ is a spatially regularized form of $(u_1,...,u_I)$ and the nonlinearities $a_i$ are merely assumed to be continuous and bounded from below. Existence of global weak solutions is obtained in any space dimension. Solutions are proved to be regular and unique when the $a_i$ are locally Lipschitz continuous

Confined hidden vector dark matter

We argue that the lightest vector bound states of a confining hidden sector communicating with the Standard Model through the Higgs portal are stable and are viable candidates of dark matter. The model is based on an SU(2) gauge group with a scalar field in its fundamental representation and the stability of the lightest vector bound state results from the existence of a custodial symmetry. As the relic density depends essentially on the scale of confinement in the hidden sector, Lambda_HS, agreement with WMAP abundance requires Lambda_HS in the 20-120 TeV range.Comment: 6 page