7,826 research outputs found
Colour Reconnection at LEP2
Colour reconnection is the final state interaction between quarks from
different sources. It is not yet fully understood and is a source of systematic
error for W-boson mass and width measurements in hadronic \WW decays at LEP2.
The methods of measuring this effect and the results of the 4 LEP experiments
at 183\gev\leq\rts\leq 202\gev will be presented.Comment: 6 pages, 1 table, 7 figures, Symposium, ISMD2000, Typos fixed (proof
reading by editor
Modular representations in type A with a two-row nilpotent central character
We study the category of representations of in
positive characteristic, whose p-character is a nilpotent whose Jordan type is
the two-row partition (m+n,n). In a previous paper with Anno, we used
Bezrukavnikov-Mirkovic-Rumynin's theory of positive characteristic localization
and exotic t-structures to give a geometric parametrization of the simples
using annular crossingless matchings. Building on this, here we give
combinatorial dimension formulae for the simple objects, and compute the
Jordan-Holder multiplicities of the simples inside the baby Vermas (in special
case where n=1, i.e. that a subregular nilpotent, these were known from work of
Jantzen). We use Cautis-Kamnitzer's geometric categorification of the tangle
calculus to study the images of the simple objects under the [BMR] equivalence.
The dimension formulae may be viewed as a positive characteristic analogue of
the combinatorial character formulae for simple objects in parabolic category O
for , due to Lascoux and Schutzenberger
Categorification via blocks of modular representations II
Bernstein, Frenkel and Khovanov have constructed a categorification of tensor
products of the standard representation of using singular
blocks of category for . In earlier work, we
construct a positive characteristic analogue using blocks of representations of
over a field of characteristic , with
zero Frobenius character, and singular Harish-Chandra character. In the present
paper, we extend these results and construct a categorical
-action, following Sussan's approach, by considering more
singular blocks of modular representations of . We consider
both zero and non-zero Frobenius central character. In the former setting, we
construct a graded lift of these categorifications which are equivalent to a
geometric construction of Cautis, Kamnitzer and Licata. We establish a Koszul
duality between two geometric categorificatons constructed in their work, and
resolve a conjecture of theirs. For non-zero Frobenius central characters, we
show that the geometric approach to categorical symmetric Howe duality by
Cautis and Kamnitzer can be used to construct a graded lift of our
categorification using singular blocks of modular representations of
.Comment: 24 page
- …