O pátém Hilbertově problému (existence struktury Lieovy grupy na lokálně euklidovské topologické grupě)
Attempts to extend our previous work using the octonions to describe fundamental particles lead naturally to the consideration of a particular real, noncompact form of the exceptional Lie group , and of its subgroups. We are therefore led to a description of in terms of octonionic matrices, generalizing previous results in the case. Our treatment naturally includes a description of several important subgroups of , notably , , and (the double cover of) . An interpretation of the actions...
We study the densities of the semigroup generated by the operator on the 3-dimensional Heisenberg group. We show that the 7th derivatives of the densities have a jump discontinuity. Outside the plane x=0 the densities are . We give explicit spectral decomposition of images of in representations.
Let be an irreducible lattice in a product of simple groups. Assume that has a factor with property (T). We give a description of the topology in a neighbourhood of the trivial one dimensional representation of in terms of the topology of the dual space of .We use this result to give a new proof for the triviality of the first cohomology group of with coefficients in a finite dimensional unitary representation.
Let be a connected and simply connected Banach–Lie group. On the complex enveloping algebra of its Lie algebra we define the concept of an analytic functional and show that every positive analytic functional is integrable in the sense that it is of the form for an analytic vector of a unitary representation of . On the way to this result we derive criteria for the integrability of -representations of infinite dimensional Lie algebras of unbounded operators to unitary group representations.For...
This is a small survey paper about connections between the arithmetic and geometric properties in the case of arithmetic Fuchsian groups.