SIAM SEAS 2001 (Homepage of Martin Bohner)
B. Kaymakcalan and myself
are organizing a special session on
Dynamic Equations on Time Scales
at the
SIAM SEAS Annual Conference
at Coastal Carolina University in Myrtle Beach, SC, March 16-17, 2001.
CLICK HERE for some pictures courtesy of Roman Hilscher
Participating speakers were as follows:
- Martin Bohner, University of Missouri, Rolla, Missouri
- Roman Hilscher, Michigan State University, East Lansing, Michigan
- Jo Hoffacker, University of Nebraska, Lincoln, Nebraska
- Billur Kaymakcalan, Georgia Southern University, Statesboro, Georgia
- Bonita Lawrence, University of South Carolina, Beaufort, South Carolina
- Ronald Mathsen, North Dakota State University, Fargo, North Dakota
Titles and Abstracts of the talks were as follows:
- Martin Bohner:
Laplace Transform and Z-Transform: Unification and Extension.
We start this talk by recalling the concepts of the Laplace transform and
Z-transform as methods to solve higher order differential and difference
equations with constant coefficients. Then we introduce the Laplace
transform for an arbitrary time scale. Two particular
choices of time scales, namely the reals and the integers, yield the concepts
of the classical Laplace transform and of the classical Z-transform. Other
choices of time scales yield new concepts of our Laplace transform, which can
be applied to find solutions of higher order linear dynamic equations with
constant coeffficients. We present several useful properties of our Laplace
transform and offer formulas for the Laplace transforms of many elementary
functions, among them results for the convolution of two functions on a time
scale, which is introduced in this talk as well.
- Roman Hilscher:
A Wirtinger type inequality and nonoscillation of dynamic equations on time scales.
Wirtinger type inequalities
play an important role in the investigation of nonoscillatory properties of
higher order Sturm-Liouville differential equations. Recently, discrete
versions of such Wirtinger type inequalities have
been derived and used to obtain parallel
nonoscillation results for higher order Sturm-Liouville difference
equations. We derive a similar Wirtinger type inequality on an arbitrary
time scale and prove the nonoscillation of certain second order dynamic
equations. However, strong limitations occur when trying to apply the result
to higher order dynamic equations.
- Jo Hoffacker:
Green's function and eigenvalue comparisons for focal boundary value
problems on time scales.
The Green's function and its sign are developed for a nth order focal
boundary value problem. This is then used to do eigenvalue comparisons
for other focal BVPs.
- Billur Kaymakcalan:
Coupled Solutions and Monotone Iterative Techniques for some Nonlinear
Initial Value Problems on Time Scales.
A unified approach to monotone iterative technique concerning the
existence of coupled maximal and minimal solutions for dynamic equations
on time scales is developed in the case of the nonlinear term involved
admitting a splitting of a difference of two monotone functions.
Relevance of such problems in mathematical biology using both the
differential and difference form of the Logistic equation is pointed out
as an example and further features of the technique as well as other
examples are presented in the proceeding talk by the joint author.
- Bonita Lawrence:
Monotone Iterative Techniques for Dynamic Equations on Periodic Time
Scales.
Using the Monotone Iterative Technique introduced in the previous talk
by the joint author we present further features of this method and use
them to analyze the boundedness behavior of some nonlinear
dynamic equations on periodic time scales arising from mathematical
biology.
- Ronald Mathsen:
Factoring Linear Delta-Differential Operators and Oscillation
of Neutral Delta-Differential Operators on Time Scales.
We introduce nth order Delta-differential operators on time
scales and show Abel's Theroem. Then we construct both the Polya
factorization and the Trench Factorization of disconjugate operators.
Next we discuss the extension to time scales of oscillation results for
neutral differential delay equations and develop two oscillation
theorems which are new even when the time scale is the reals. We
conclude with examples illustrating these results.