Abstract
Leibniz, l’Hôpital, and Lacroix were aware that non-integer or fractional derivatives could be meaningful, but it was Niels Henrik Abel who first gave a general definition. This was in one of his first papers, published in Norwegian, but forgotten in his collected works in 1839 (in French). While ordinary derivatives describe change, non-integer derivatives describe complexity as they involve a memory of the history of the function. Power-law descriptions in time and frequency are central. Fractional derivatives occur naturally in physics, and I will present some examples from dielectrics, turbulence, acoustics, and linear viscoelasticity.
Biography
Sverre Holm (PhD 1982 NTNU) is a professor of signal processing/acoustic imaging at UIO, in Informatics since 1995 and from 2020 in Physics. He is a member of the Norwegian Academy of Technological Sciences and has industry experience from several ultrasound companies. In recent years, his research interest has been modeling of wave propagation in complex media and he published the book “Waves with Power-Law Attenuation”, Springer, in 2019.
First, there will a celebration of prof. Dag Kristian Dysthe, being the recipient of the 2023 Education award. We will be serving a delicious cake, and there will be some congratulatory words by the department. The talk follows shortly after.