Special Session 15: On the dynamics of hyperbolic partial differential equations: theory and applications

Bernstein`s Problem and Positivity Preserving Exponential Integrators for Evolution Equations
Rachid Ait Haddou
King Fahd University of Petroleum and Minerals
Saudi Arabia
Co-Author(s):    Huda Altamimi
Abstract:
Bernstein`s problem asks for the maximum positive real number $R$ for which an absolutely monotonic function, with a specified number of derivatives at the origin, exists on the interval $(-R,0)$. Optimal threshold factors govern the maximum allowable step-size for positivity preserving integration methods of initial-value problems. This talk establishes a link between Bernstein`s problem and optimal threshold factors and presents algorithms for computing the latter. Derivation of optimal exponential integrators of specified accuracy for evolution equations is discussed.