Seminar for Geometry, education and visualization with applications
PROGRAM
MATEMATIČKI INSTITUT SANU
Seminar geometriju, obrazovanje i vizualizaciju sa primenama
PLAN RADA ZA OKTOBAR 2019.
ČETVRTAK, 24.10.2019. u 17:15, Matematički institut SANU, sala 301f
Ioana-Claudia Lazar, Politehnica University of Timisoara, Romania
MINIMAL DISC DIAGRAMS IN 5/9-COMPLEXES
We introduce and study two combinatorial curvature conditions on a simplicial complex. The first one is called the 5/9-condition. We give hereby an application of another combinatorial condition, called 8-location, introduced by Damian Osajda. We prove the minimal filling diagrams lemma for 5/9-complexes.Then we show that the 5/9-condition on a simplicial complex implies the Gromov hyperbolicity of its universal cover. The second condition is called t-uniformness.
We prove that the lengths of spheres in t-uniform complexes are the terms of certain Lucas sequences. We find optimal constants for the linear isoperimetric inequality in the hyperbolic case.
Zajednicki sastanak sa KGTA Seminrom
ČETVRTAK, 31.10.2019. u 17:15, Matematički institut SANU, sala 301f
Filip Jeftić, Matematički Institut SANU
POLITOPALNE BIROVE SFERE I KANTOROVIĆ-RUBINŠTAJNOVI POLITOPI PONDERISANIH CIKLOVA
Poznato je da je većina Birovih sfera ne-politopalna. Nasuprot tome, pokazujemo da su Birove sfere asocirane prag-kompleksima (threshold simplicial complexes) politopalne. Štaviše, pokazujemo da su zvezdolike. Uspostavljamo vezu između Birovih sfera i Kantorović-Rubinštajnovih politopa pokazujući da je granica KR-politopa asocirana poligonalnom linku (polygonal linkage i.e. weighted cycle) izomorfna Birovoj sferi asociranog simplicijanog kompleksa "kratkih skupova".
Sednice seminara odrzavaju se u zgradi Matematickog instituta SANU, Knez Mihailova 36, na trecem spratu u sali 301f.
Rukovodilac Seminara dr Stana Nikcevic
