Seminar for Geometry, education and visualization with applications

PROGRAM

ČETVRTAK, 5.12.2013. u 17:15 casova, sala 301F, MI
Miljan Knezevic, Matematicki Fakultet Beograd
Title: A NOTE ON HQC MAPPINGS AND SCHWARZ-PICK TYPE INEQUALITIES.

Abstract: We will give a short review of harmonic quasiconformal mappings theory and its relation with hyperbolic geometry. Also, we will consider which properties of HQC mappings and of hyperbolic metric are essential for validity of some Schwarz-Pick type inequalities.

ČETVRTAK, 12.12.2013. u 17:15, sala 301f, MI
Milan Zlatanovic ( PMF Nis)
Naslov: EKVITORZIONA PRESLIKAVANJA PROSTORA NESIMETRICNE AFINE KONEKSIJE

Apstrakt: Iako u definiciji geodezijskih i planarnih krivih ucestvuje samo simetricni deo koneksije, interesantno je posmatrati geodezijska, konformna i holomorfno-projektivna preslikavanja prostora sa torzijom. Nadjeni su novi invarijantni geometrijski objekti. Na predavanju ce biti pomenuta preslikavanja nekih znacajniih klasa prostora sa torzijom kao sto su ekvidistantni prostori.

ČETVRTAK, 20.12.2013. u 17:15, sala 301f, MI
Ana Zekovic
Title: GORDIAN AND SMOOTHING DISTANCES OF KNOTS

Abstrakt: One of most complicated problems in knot theory is the computation of unknotting number. Hass, Lagarias and Pippenger proved that the unknotting problem is NP. In this paper we discuss the question can we compute unknotting number from minimal knot diagrams, Bernhard-JablanConjecture, compute unknown knot distances between non-rational knots and search for minimal distances by using a graph with weighted edges representing knot distances. Since topoizomerazes are enzymes involved in changing crossing of DNA, knots distances can be used to study topoizomerazes actions. In the existing tables of knot smoothings, knots with smoothing number 1 are computed by Abe and Kanenobu for knots with at most n = 9 crossings, and smoothing knot distances are computed by Kanenobu for knots with at most n = 7 crossings. We compute some undecided knot distances 1 from these papers, and extend the computations by computing knots with smoothing number one with at most n = 11 crossings and smoothing knot distances of knots with at most n = 9 crossings. All computations are done in the program LinKnot, based on Conway notation and non-minimal representations of knots.
Autori: Slavik Jablan, Ana Zekovic

ČETVRTAK, 26.12.2013. u 17:15, sala 301f MI SANU
Milos Antic (Matematicki Fakultet Beograd)
Na predavanju biti predstavljen rad: "Bang-Yen Chen, Franki Dillen, Leopold Verstraelen, Luc Vrancken, Submanifolds of restricted type, Journal of Geometry Vol.46 (1993.)"

Apstrakt: Podmnogostrukost M^n euklidskog prostora R^m je "restrihovanog tipa" ako je operator oblika vektora glavne krivine tangentan deo fiksirane linearne transformacije od R^m. Pokazamo da je hiperpovr u R^m "restrihovanog tipa": ili minimalna povr, ili deo Dekartovog proizvoda sfere i linearnog potprostora od R^m, ili cilindar nad ravanskom krivom koja je "restrihovanog tipa". Damo i klasifikaciju ravanskih krivih "restrihovanog tipa".

Sednice seminara odrzavaju se u zgradi Matematickog instituta SANU, Knez-Mihailova 36, na trecem spratu u sali 301f.