16,676 research outputs found
Race, Power, and (In)equity Within Two-way Immersion Settings
Two-way immersion schools provide a promising model for service delivery to students who are English language learners. With the goals of bilingualism, academic excellence, and cross cultural appreciation, these schools are designed to build bridges across linguistically heterogeneous student bodies. Yet while empirical evidence demonstrates that the two-way immersion model can be effective in these regards, we know little about how such schools address other dimensions of diversity, including race, ethnicity, class, and disability. This study contributes to filling this gap by critically analyzing these dimensions in the areas of recruitment and retention in two two-way immersion schools
Homological stability for oriented configuration spaces
We prove homological stability for sequences of "oriented configuration
spaces" as the number of points in the configuration goes to infinity. These
are spaces of configurations of n points in a connected manifold M of dimension
at least 2 which 'admits a boundary', with labels in a path-connected space X,
and with an orientation: an ordering of the points up to even permutations.
They are double covers of the corresponding unordered configuration spaces,
where the points do not have this orientation. To prove our result we adapt
methods from a paper of Randal-Williams, which proves homological stability in
the unordered case. Interestingly the oriented configuration spaces stabilise
more slowly than the unordered ones: the stability slope we obtain is
one-third, compared to one-half in the unordered case (these are the best
possible slopes in their respective cases). This result can also be interpreted
as homological stability for unordered configuration spaces with certain
twisted coefficients.Comment: 36 pages, 2 figures; v2: minor changes, final version - to appear in
Trans. Amer. Math. So
The Bohl spectrum for nonautonomous differential equations
We develop the Bohl spectrum for nonautonomous linear differential equation
on a half line, which is a spectral concept that lies between the Lyapunov and
the Sacker--Sell spectrum. We prove that the Bohl spectrum is given by the
union of finitely many intervals, and we show by means of an explicit example
that the Bohl spectrum does not coincide with the Sacker--Sell spectrum in
general. We demonstrate for this example that any higher-order nonlinear
perturbation is exponentially stable, although this not evident from the
Sacker--Sell spectrum. We also analyze in detail situations in which the Bohl
spectrum is identical to the Sacker-Sell spectrum
Heavy MSSM Higgs production at the LHC and decays to WW,ZZ at higher orders
In this paper we discuss the production of a heavy scalar MSSM Higgs boson H
and its subsequent decays into pairs of electroweak gauge bosons WW and ZZ. We
perform a scan over the relevant MSSM parameters, using constraints from direct
Higgs searches and several low-energy observables. We then compare the possible
size of the pp -> H -> WW,ZZ cross sections with corresponding Standard Model
cross sections. We also include the full MSSM vertex corrections to the H ->
WW,ZZ decay and combine them with the Higgs propagator corrections, paying
special attention to the IR-divergent contributions. We find that the vertex
corrections can be as large as -30% in MSSM parameter space regions which are
currently probed by Higgs searches at the LHC. Once the sensitivity of these
searches reaches two percent of the SM signal strength the vertex corrections
can be numerically as important as the leading order and Higgs self-energy
corrections and have to be considered when setting limits on MSSM parameters
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