Nebraska-Iowa Iowa-Nebraska Functional Analysis Seminar

General Format

This is a one-day mathematics conference held once or twice a year, usually in April and October in Des Moines, Iowa. The format consists of four hour-long talks, with a one-and-a-half or two hour lunch. between the 2nd and 3rd talk. The first talk typically starts at 11:00 am and the last talk finishes about 5:00 pm.

We usually meet at The University of Iowa John and Mary Pappajohn Education Center, located at 1200 Grand Ave., Des Moines, IA 50309. Here is a map.

The conference first met in March of 1994; the April 2014 meeting represented the twentieth year and the twenty-seventh meeting. (There have not been two meetings every year.)

It is jointly organized by the Mathematics Departments of Creighton University, Iowa State University, The University of Iowa, and The University of Nebraska-Lincoln. Faculty and students from a number of other nearby universities also attend. All are welcome. There is no registration fee. If you have any questions, please contact one of the organizers.


Randall Crist of Creighton
Raul Curto of Iowa
Yiu T Poon of Iowa State
Allan Donsig of Nebraska-Lincoln

Next Meeting: April 8, 2017 in Omaha, Nebraska

Roger Smith (of Texas A&M University)
Title: A Galois Correspondence for Crossed Products
Abstract: If a discrete group G acts on an operator algebra A (C* or von Neumann) the question arises of whether the algebras between A and its crossed product by G can be characterized by subgroups of G. When A is a simple C*-algebra and G acts by outer automorphisms, a positive answer has been given by Landstad-Olesen-Pedersen when G is abelian, by Choda (with some rather restrictive extra hypotheses) and by Izumi when G is finite. In this talk I will give a positive solution for all discrete groups G and discuss some consequences. This is joint work with Jan Cameron.
Daniel Freeman (of St. Louis University)
Title: The Discretization Problem for Continuous Frames
Abstract: Functions on L2([0, 1]) can be analyzed continuously through the Fourier transform, or discretely through Fourier series and sampling the Fourier transform only at the integers. The discretization problem essentially asks what other continuous representations can be sampled to obtain discrete representations. We solve this problem by giving a complete characterization of when a continuous frame for a Hilbert space may be sampled to obtain a discrete frame. In particular, every bounded continuous frame may be sampled to obtain a discrete frame. This is joint work with Darrin Speegle.
Gabriel Nagy (of Kansas State University)
Title: Essential inclusions revisited - preliminary report
Abstract: Call a C*-algebra inclusion A ⊂ B essential, if there is no non-trivial closed two sided ideal J ⊂ B, such that J ∩ A is empty. Over the past five years or so (joint works with Brown, Reznikoff, Sims and Williams), most examples of such inclusions were produced by investigating the space of states on A that extend uniquely to states on B. I will try to explain why conceptually (but not literally!), this is the only technique that works, if it is suitably adapted to the case when the above mentioned state space is rather small (or even empty!). As an application, we provide a simplicity criterion for reduced C*-algebras of etale groupoids. (Joint work with Danny Crytser)
Lance Nielsen (of Creighton University)
Title: Feynman's Operational Calculus: Introduction and Essential Properties
Abstract: After some background and history related to Feynman’s development of his operational calculus, the Jefferies-Johnson approach to the operational calculus will be introduced. We will then survey some important results and applications of the operational calculus, including a look at stability properties as well as evolution/generalized integral equations satisfied by the operational calculus.

NOTE: We will be meeting in Omaha, on the campus of Creighton University, in the Hixson-Lied Science Building, Room 522. (campus map). The conference will start at 1pm and finish by 5pm or so. There will be a dinner afterwards.

Detailed driving directions: Off I-80, take I-480 North. Go about 3 miles and take the exit onto Hwy 75 North. Take the first exit off Hwy 75 onto Cumming St. Turn right at the lights onto Cumming St. (now heading east). Head east about 0.3 miles to 24th ST. Turn right on 24th St. (now heading south). Take the next right onto Burt St. (heading west). Drive about 0.1-0.2 miles and find street parking or park in the lot north of Burt. We will be meeting in the Eppley Bldg. Eppley is south of Burt, visible from the street, and labeled in large letters. Meeting will be on the 3rd floor in Room 309.

Speakers and Titles from Previous Meetings

October 17, 1998
Gary Weiss (of University of Cinncinnati) Madras, India)
Title: The commutator structure of operator ideals and unitarily invariant trace extensions beyond the trace class
Michael Lamourexu (of University of Calgary)
Title: Ideals in Continuous Crossed products
Paul Muhly (of University of Iowa)
Title: On the Morita equivalence of C*-correspondences
Roger Smith (of Texas A&M University)
Title: Cohomology of von Neumann algebras with Cartan subalgebras

October 11, 1997
May Nilsen (of the University of Nebraska-Lincoln)
Title: Hopf C*-algebras
Randall Crist (of Creighton University)
Title: Derivations on TAF Algebras
Nik Weaver (of Washington University in St. Louis)
Title: Metrics from the Point of View of Functional Analysis)
Radu Gologan (of the University of Iowa and the Institute of Mathematics of Romanian Academy of Sciences)
Title: Pointwise Ergodic Theorems

April 26, 1997
Teresa Bermudez (of the University of Iowa and University de Laguana, Spain)
Title: Some Results in Local Spectral Theory
Dale Buske (of Iowa State University and St. Cloud State University)
Title: Hilbert Modules over a class of Semicrossed Products
Bryan Cain (of Iowa State University)
Title: Operator Equations, Inertia, and Stability
Eui-Chai Jeong (of the University of Iowa)
Title: Decomposition of the Cuntz Algebra Representation