863 research outputs found
Multiple solutions to logarithmic Schrodinger equations with periodic potential
We study a class of logarithmic Schrodinger equations with periodic potential
which come from physically relevant situations and obtain the existence of
infinitely many geometrically distinct solutions.Comment: 3 pages, corrigendum to version
Ground states of critical and supercritical problems of Brezis-Nirenberg type
We study the existence of symmetric ground states to the supercritical
problem in a domain of the form where is a bounded smooth
domain such that and
is the -st critical exponent. We show that
symmetric ground states exist for in some interval to the left of
each symmetric eigenvalue, and that no symmetric ground states exist in some
interval with if
Related to this question is the existence of ground states to the anisotropic
critical problem where are positive continuous functions on
We give a minimax characterization for the ground states
of this problem, study the ground state energy level as a function of
and obtain a bifurcation result for ground states
Ethnic Segregation and Educational Outcomes in Swedish Comprehensive Schools
We ask whether ethnic density in Swedish comprehensive schools affect teacher-assigned school grades in ninth grade (age 16). The data, based on two entire cohorts who graduated in 1998 and 1999 (188,000 pupils and 1,043 schools), link school information with Census data on social origin, and enable us to distinguish first- from second generation immigrants. Using multilevel analysis we find the proportion of first, but not the second, generation immigrant pupils in a school to depress grades in general, but particularly for (first generation) immigrant pupils. Passing a threshold of more than 40 percent immigrants reduces grades with around a fifth of a standard deviation, affecting fourteen percent of immigrant children. Our main results are robust to model specifications which address omitted variable bias both at individual- and school-level. One policy implication of our results is that desegregation policies which concentrated on the two per cent most segregated schools would probably improve school results and reduce ethnic inequality.Ethnic inequality; Immigrant schooling; Educational attainment; Contextual effects; Ethnic inequality; Immigrant schooling
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