Seminar for Geometry, education and visualization with applications
MATEMATIČKI INSTITUT SANU
Seminar geometriju, obrazovanje i vizualizaciju sa primenama
PLAN RADA ZA DECEMBAR 2018.
ČETVRTAK, 05.12.2018. u 14:00, Matematički institut SANU, sala 301f
Ljubica Velimirovic, Faculty of Sciences and Mathematics,Nis
ON KNOTS AND ENERGIES
This is talk based on the joint research with Louis Kauffman, Marija Najdanovic and Svetozar Rancic.Knot theory is the study of mathematical models of knotting phenomena, often motivated by considerations from biology, chemistry, and physics (Kauffman 1991). Physical knot theory is used to study how geometric and topological characteristics of filamentary structures, such as magnetic flux tubes, vortex filaments, polymers, DNA's, influence their physical properties and functions. It has applications in various fields of science, including topological fluid dynamics, structural complexity analysis and DNA biology (Kauffman 1991 , Ricca 1998,).
Traditional knot theory models a knot as a simple closed loop in three-dimensional space. Such a knot has no thickness or physical properties such as tension or friction. Physical knot theory incorporates more realistic models.
The talk is devoted to the shape descriptors of knots during infinitesimal bending. The problem of infinitesimal bending of knots is a special part of the theory of deformation. Bending theory considers bending of manifolds, isometric deformations as well as infinitesimal bending. It requires use of differential geometry, mechanics, physics and has applications in modern computer graphics. Infinitesimal bending is "almost" an isometric deformation, or it is an isometric deformation in a precise approximation. Arc length is stationary under infinitesimal bending with a given precision.
We will discussed here: M\" obius energy, Willmore energy, Total curvature, Total torsion, Total normalcy. Some examples are visualised developed by Svetozar Rancic and coauthors.Instead of using existing software capable to do symbolic and numeric calculations, we decided to develop our own software tool in Visual C++.
ČETVRTAK, 13.12.2018. u 17:15, Matematički institut SANU, sala 301f
Vladica Andrejić, Matematički Fakultet
OSNOVE PSEUDO-RIMANOVE GEOMETRIJE
Posmatraćemo nedefinitni skalarni proizvod, definiciju i osnovna tvrđenja. Razmotrićemo ponašanje izotropnih vektora i skroz izotropnih prostora. Videćemo kako možemo napraviti neke pseudo-Rimanove mnogostrukosti, kao i pod kojim uslovima glatka mnogostrukost dozvoljava nedefinitnu metriku.
Sednice seminara odrzavaju se u zgradi Matematickog instituta SANU, Knez Mihailova 36, na trecem spratu u sali 301f.
Rukovodilac Seminara dr Stana Nikcevic