Two-dimensional electron system in high magnetic fields: Wigner crystal vs. composite-fermion liquid

The two dimensional system of electrons in a high magnetic field offers an opportunity to investigate a phase transition from a quantum liquid into a Wigner solid. Recent experiments have revealed an incipient composite fermion liquid in a parameter range where theory and many experiments had previously suggested the Wigner crystal phase, thus calling into question our current understanding. This Letter shows how very small quantitative corrections (< 1%) in the energy due to the weak interaction between composite fermions can cause a fundamental change in the nature of the ground state, thus providing insight into the puzzling experimental results.Comment: 4 pages, 2 figure

Coincidence of some classes of universal functions

Let &#937; a domain in the complex plane such that &#937; satisfies appropriate geometrical and topological properties. We prove that if f is a holomorphic function in &#937;, then its Taylor series, with center at any &#958; &#1028; &#937; , is universal with respect to overconvergence if and only if its Cesáro (C, k)-means are universal for any real k > &#8722;1. This is an extension of the same result, proved recently by F. Bayart, for any integer k &#8805; 0. As a consequence, several classes of universal functions introduced in the related literature are shown to coincide.Let &#937; a domain in the complex plane such that &#937; satisfies appropriate geometrical and topological properties. We prove that if f is a holomorphic function in &#937;, then its Taylor series, with center at any &#958; &#1028; &#937; , is universal with respect to overconvergence if and only if its Cesáro (C, k)-means are universal for any real k > &#8722;1. This is an extension of the same result, proved recently by F. Bayart, for any integer k &#8805; 0. As a consequence, several classes of universal functions introduced in the related literature are shown to coincide

Wavelet-transform-based strategy for generating new Chinese fonts

Author name used in this publication: Chi K. TseRefereed conference paper2002-2003 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Tropicalization and irreducibility of Generalized Vandermonde Determinants

We find geometric and arithmetic conditions in order to characterize the irreducibility of the determinant of the generic Vandermonde matrix over the algebraic closure of any field k. We also characterize those determinants whose tropicalization with respect to the variables of a row is irreducible.Comment: 10 pages, AMSart. Revised version to appear in Proceedings of the AM

Children of prisoners: exploring the impact of families' reappraisal of the role and status of the imprisoned parent on children's coping strategies

Qualitative data from a larger study on the impact of parental imprisonment in four countries found that children of prisoners face fundamentally similar psychological and social challenges. The ways that children cope, however, are influenced by the interpretative frame adopted by the adults around them, and by how issues of parental imprisonment are talked about in their families. This article argues that families have to reappraise their view of the imprisoned parent and then decide on their policy for how to deal with this publicly. Their approach may be based on openness and honesty or may emphasise privacy and secrecy, or a combination of these. Children are likely to be influenced by their parents'/carers' views, although these may cause conflict for them. Where parents/carers retain a positive view of the imprisoned parent, children are likely to benefit; where parents/carers feel issues of shame and stigma acutely, this is likely to be transmitted to their children. This is important for social workers and practitioners involved in supporting prisoners' families and for parenting programmes