Seminarier 1997/98

27 augusti 1997: KASS-gruppen; Planering av höstens verksamhet
11 september 1997: Yasha Eliashberg, Stanford University, USA; Topology of 2-knots and Symplectic geometry
12 september 1997: Yasha Eliashberg, Stanford University, USA; Contact Structures on 3-manifolds
17 september 1997: Bo Berndtsson; Asymptotically holomorphic funtions in several variables. (Joint with M. Andersson.)
24 september 1997: Nikolay Shcherbina; Pseudoconcave pluripolar sets in C² (after N. Levenberg & Z. Slodkowski).
1 oktober 1997: Nikolay Shcherbina; Pseudoconcave pluripolar sets in C² (after N. Levenberg & Z. Slodkowski), cont'd.
8 oktober 1997: Mats Andersson; Non-holomorphic functional calculus for several commuting operators.
This is a continuation of the KASS seminar 17/9, but no precise memories from this talk will be required. Let a₁,...,a_n be bounded operators on a Banach space, with joint spectrum \sigma(a)\subset Cⁿ. We discuss the resolvent \omega_z-\alpha, which is an operator-valued Dolbeault cohomology class in Cⁿ\ \sigma(a). In the case when \sigma(a)\subset Rⁿ and with a certain growth condition on ||\omega_z-a|| we can extend the wellknown holomorphic functional calculus to a larger one, containing nonholomorphic functions. In particular, we present a sharp condition for the existence of a non-quasianalytic functional calculus.
15 oktober 1997: Nikolay Shcherbina; A non-removable generic 4-ball in the unit sphere of C³ (joint with B. Jöricke)
22 oktober 1997: Nikolay Shcherbina; A non-removable generic 4-ball in the unit sphere of C³ (joint with B. Jöricke), continued
29 oktober 1997: Johan Karlsson; The Montessus de Ballore theorem in several variables
It has long been known that the Montessus de Ballore theorem on convergence of rational interpolants is only true in one dimension. None the less a candidate for the name has recently been proved. The trick should sound familiar to numerical analysts: Instead of interpolating, obtain a least squares solution of an unsolvable interpolation problem.
19 november 1997: Bo Berndtsson; Komplex dynamik i flera variabler (efter Mattias Jonsson)
26 november 1997: Bo Berndtsson; Komplex dynamik i flera variabler (efter Mattias Jonsson), forts.
3 december 1997: Mats Andersson; Simplexfunktionaler och Fantappiètransformen
10 december 1997: Mats Andersson; Simplexfunktionaler och Fantappiètransformen, forts
22 januari 1998: Aline Bunami, Université d'Orleans; TBA
23 januari 1998: Thomas hansson; Disputation: On Represenation Theorems for Hardy Spaces in Several Complex Variables.
28 januari 1998: Bo Berndtsson; Ickeexistens av Leviplatta hyperytor i P² (efter Ohsawa-Sibony).
11 februari 1998: Nikolay Shcherbina; The Dirichlet problem for Levi-flat graphs over unbounded domains (Joint with G. Tomassini)
18 februari 1998: Nikolay Shcherbina; The Dirichlet problem for Levi-flat graphs over unbounded domains, continued
18 mars 1998: Mats Aigner; The Ginzburg-Landau vortex equation in R²
1 april 1998: Jie Xiaou, Uppsala; The Q_p corona theorem.
For p\in (0,1), let Q_p be the subspace of Möbius bounded functions in the Dirichlet type space. Based on the study of multipliers on Q_p we establish the corona theorem for Q_p.
14 april 1998: John Wermer, Brown University; Linking numbers and boundaries of analytic varieties.
21 april 1998: Finnur Larusson, Western Ontario; Holomorphic functions of slow growth on nested covering spaces of complex manifolds.
22 april 1998: G. Tomassini, Scuola Normale Superiore (Pisa); Subsets of C² and Parabolic Problem for the Levi Equation
24-26 april 1998: Nordan-98
29 april 1998: Cladio Rea (Rom); Smooth CR-maps
6 maj 1998: Andrei Domrin, Moskva; Holomorphic functions and embedded real surfaces (after S. Nemirovski)
The talk is devoted to the study of necessary and sufficient topological conditions for an embedded real surfaceto lie in a strictly pseudoconvex domain on a complex surface. These results are used to construct Stein domains on algebraic manifolds and to describe envelopes of holomorphy of real surfaces in CP² and in some other complex surfaces.
13 maj 1998: Nikolay Kruzhilin, Moskva; Realization in C² of Stein surfaces fibered over a disc.
The problem of the realization of a Stein manifold fibered over a planar domain as a (fibered) subdomain of a linear space is discussed. An example of a 2-dimensional manifold fibered by discs but not equvialent to a subdomain of C² is constructed.
14 maj 1998: Jeff McNeal, Ohio State University; Global regularity of the $\bar\partial$-Neumann problem
15 maj 1998: Henrik Delin; Disputation: Weighted Estimates in Complex Analysis and some Inequalities in Riemannian Geometry
This thesis deals with problems from two different fields of mathematics in the four included papers. The first two papers treat problems from harmonic analysis on Riemannian manifolds. Papers 3 and 4 give weighted estimates related to the $\bar\partial$ equation in several complex variables, and should be considered the main part of this thesis.