On multiplicities for SL(n)

We use the strong Artin conjecture for Galois extensions of Heisenberg type to show that a cuspidal automorphic representation of SL(N)/F, forF a number field andN>2, can occur with multiplicity greater than one. We also exhibit two cuspidalL-packets (forF=Q andN prime) which are locally isomorphic for primesp different fromN, but which are disjoint atN, i.e. thatL-packets are not rigid.     

SL(n,C)中的一些特殊可解子群及应用

给出了SL(n,C)中的几类特殊可解子群,并应用于Fuchs系统.由Fuchs方程的单值群的可解性与其可积性的关系,给出了其可积的一些条件.     

Similarity over SL(n, F)

Let F be a finite field. It is shown that if AB axe n × n matrices with entries from F which are similar over GL(n, F), then AB are similar over SL(n, F), provided that some elementary divisor of xl- A is irreducible over F. The result remains true if F is any field such that any element of F may be represented as the norm of an element of any finite algebraic extension of F.     

Reducibility of the elementary representations for SL (n,R) and GL(n,R)

Functional Analysis and Its Applications -     

The Triangulated Hopf Category n +SL(2)

We discuss an example of a triangulated Hopf category related to SL(2). It is an equivariant derived category equipped with multiplication and comultiplication functors and structure isomorphisms. We prove some coherence equations for structure isomorphisms. In particular, the Hopf category is monoidal.     

Similarity of matrices under SL(n,K)

Take a similarity class of n × n matrices over a field K Let p_i ,(λ) ^m(i) be the elementary divisors L_i , = K [λ]/(p_i ). Under conjugation by SL(n, K), the class splits into subclasses corresponding to the elements of K^×/Π(NL _i ^×) ^m(i).     

Distribution results for lattices in SL(2,ℚ p )

In this paper we study the ergodic properties of the linear action of lattices Γ of SL(2,ℚ_p) on ℚ_p × ℚ_p and distribution results for orbits of Γ. Following Serre, one can define a “geodesic flow” for an associated tree (actually associated to GL(2,ℚ_p)). The approach we use is based on an extension of this approach to “frame flows” which are a natural compact group extension of the geodesic flow.     

Stochastic flows on the boundaries of SL(n,R)

Summary We study the asymptotic stability of the stochastic flows on a class of compact spaces induced by a diffusion process in SL(n, R) or GL(n, R). These compact spaces are called boundaries of SL(n, R), which include SO(n), the flag manifold, the sphereS ⁿ–1 and the Grassmannians. The one point motions of these flows are Brownian motions. For almost every, , we determine the set of stable points. This is a random open set whose complement has zero Lebesgue measure. The distance between any two points in the same component of this set tends to zero exponentially fast under the flow. The Lyapunov exponents at stable points are computed explicitly. We apply our results to a stochastic flow onS ⁿ–2 generated by a stochastic differential equation which exhibits some nice symmetry.Research supported in part by Hou Yin Dong Education Foundation of China On leave from Nankai University, Tianjin, China     

2-Cohomologies of the groups SL(n, q)

Let G = SL(n, q), where q is odd, V be a natural module over G, and L = S²(V) be its symmetric square. We construct a 2-cohomology group H²(G, L). The group is one-dimensional over F _q if n = 2 and q ≠ 3, and also if (n, q) = (4, 3). In all other cases H²(G, L) = 0. Previously, such groups H²(G, L) were known for the cases where n = 2 or q = p is prime. We state that H²(G, L) are trivial for n ⩾ 3 and q = p^m, m ⩾ 2. In proofs, use is made of rather elementary (noncohomological) methods. __________ Translated from Algebra i Logika, Vol. 47, No. 6, pp. 687–704, November–December, 2008.     

Some new results on sets of type (m,n) in projective planes

All possible sets of type (l,n) in a finite projective plane are completely characterized from the arithmetical point of view. Furthermore, necessary existence conditions are proved for sets of type (m,n) which are stronger then the previously known ones and provide the unique possible arithmetical solutions whenever they are satisfied.     

(2,3)-Generation of SL(n,q).I. cases n=5,6,7

In this paper we prove that the groupws SL(n,q), q=p^m, are factors of the modular groups PSL(2,Z) When n=5,6,7 and P≠2, q≠9     

On Isometric Actions of SL(n,Z) on Three-Dimensional Visibility Manifolds

Let X be a three-dimensional, visibility manifold. Suppose L(n,Z), n3 acts on X by isometries. Then either the action is trivial or a point in the boundary of X is fixed by the action.     

An example of an SL2-Hilbert scheme with multiplicities

In [AB05], Alexeev and Brion have introduced the notion of invariant Hilbert schemes. We determine the invariant Hilbert scheme of the zero fibre of the moment map of an action of SL₂ on ( mathbbC² ) ^?6 {left( {{mathbb{C}^2}} right)^{ oplus 6}} as one of the first examples of invariant Hilbert schemes with multiplicities. While doing this, we present a general procedure for realizing these calculations. We also consider questions of smoothness and connectedness and thereby show that our Hilbert scheme gives a resolution of singularities of the symplectic reduction of the action.