scholarly journals The Bott–Borel–Weil Theorem for direct limit groups

2001 ◽  
Vol 353 (11) ◽  
pp. 4583-4622 ◽  
Author(s):  
Loki Natarajan ◽  
Enriqueta Rodríguez-Carrington ◽  
Joseph A. Wolf
2016 ◽  
Vol 58 (3) ◽  
pp. 739-752
Author(s):  
CHRIS CAVE ◽  
DENNIS DREESEN

AbstractWe give a means of estimating the equivariant compression of a group G in terms of properties of open subgroups Gi ⊂ G whose direct limit is G. Quantifying a result by Gal, we also study the behaviour of the equivariant compression under amalgamated free products G1∗HG2 where H is of finite index in both G1 and G2.


1991 ◽  
Vol 23 (2) ◽  
pp. 99-109 ◽  
Author(s):  
Loki Natarajan ◽  
Enriqueta Rodr�guez-Carrington ◽  
Joseph A. Wolf

2011 ◽  
Vol 63 (6) ◽  
pp. 1307-1327 ◽  
Author(s):  
Ivan Dimitrov ◽  
Ivan Penkov

AbstractA diagonal ind-group is a direct limit of classical affine algebraic groups of growing rank under a class of inclusions that contains the inclusionas a typical special case. If G is a diagonal ind-group and B ⊂ G is a Borel ind-subgroup, we consider the ind-variety G/B and compute the cohomology H𝓁(G/B,𝒪−λ) of any G-equivariant line bundle 𝒪−λ on G/B. It has been known that, for a generic λ, all cohomology groups of 𝒪−λ vanish, and that a non-generic equivariant line bundle 𝒪−λ has at most one nonzero cohomology group. The new result of this paper is a precise description of when Hj (G/B,𝒪−λ) is nonzero and the proof of the fact that, whenever nonzero, Hj (G/B,𝒪−λ) is a G-module dual to a highest weight module. The main difficulty is in defining an appropriate analog WB of the Weyl group, so that the action of WB on weights of G is compatible with the analog of the Demazure “action” of the Weyl group on the cohomology of line bundles. The highest weight corresponding to Hj (G/B,𝒪−λ) is then computed by a procedure similar to that in the classical Bott–Borel–Weil theorem.


1980 ◽  
Vol 86 (2) ◽  
pp. 471-476 ◽  
Author(s):  
Kenneth Goodearl ◽  
Thomas Rushing
Keyword(s):  

2021 ◽  
pp. 2150030
Author(s):  
Marouane Rabaoui

In this paper, we study the first-order cohomology space of countable direct limit groups related to Olshanski spherical pairs, relatively to unitary representations which do not have almost invariant vectors. In particular, we prove a variant of Delorme’s vanishing result of the first-order cohomology space for spherical representations of Olshanski spherical pairs.


2007 ◽  
Vol 154 (6) ◽  
pp. 1126-1133 ◽  
Author(s):  
Helge Glöckner
Keyword(s):  

2014 ◽  
Vol 24 (02) ◽  
pp. 207-231
Author(s):  
Brent B. Solie

Let Γ be a fixed hyperbolic group. The Γ-limit groups of Sela are exactly the finitely generated, fully residually Γ groups. We introduce a new invariant of Γ-limit groups called Γ-discriminating complexity. We further show that the Γ-discriminating complexity of any Γ-limit group is asymptotically dominated by a polynomial.


2019 ◽  
Vol 2019 (749) ◽  
pp. 65-86
Author(s):  
Pete L. Clark ◽  
Allan Lacy

Abstract We show that a nontrivial abelian variety over a Hilbertian field in which the weak Mordell–Weil theorem holds admits infinitely many torsors with period any given n>1 that is not divisible by the characteristic. The corresponding statement with “period” replaced by “index” is plausible but open, and it seems much more challenging. We show that for every infinite, finitely generated field K, there is an elliptic curve E_{/K} which admits infinitely many torsors with index any given n>1 .


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