Hajós Seminar

The seminar was initiated by Prof. Dr. Károly Bezdek (at the Dept. of Geometry, Eötvös University). It is devoted to research work in Combinatorial Geometry, Discrete Geometry, Convex Geometry and Differential Geometry with applications. The participants are undergraduate and graduate students including faculty members at Eötvös University.
At present the seminar is led by Prof. János Szenthe.


Dept. of Geometry, Eötvös University,
H-1117 Budapest, Pázmány Péter sétány 1/C
Lecture Room 4-713
On Thursdays 10:00-12:00


Program for the Fall Semester 2018




November 29:
Balázs Csikós ( Budapest ) " About the total scalar curvature of tubes around curves in 3D Riemannian manifolds "
November 15:
András Némethi ( Budapest ) " Algebraic plane curves "
November 8:
Földvári Viktória ( Budapest ): " Legendre knots "
October 18:
Balázs Csikós ( Budapest ): " Two demonstrations of the Jordan-theorem (II) "
October 11:
Balázs Csikós ( Budapest ): " Two demonstrations of the Jordan-theorem (I) "
September 27:
Gyula Lakos ( Budapest ): " A normal form of the elements of GL(2,R) "




Past Attractions for the Spring Semester 2018



May 31:
Károly Bezdek ( Calgary, Budapest ): " On totally separable translative packings "
May 17:
Dániel Varga ( Budapest ): " Machine learning in hyperbolic spaces "
February 15:
Árpád Kurusa ( Szeged ): " Projective metrics and quadratic surfaces and curves "



Past Attractions for the Fall Semester 2017



November 9:
Zsolt Lángi ( Budapest ): " Inequalities for totally separable packings "
October 26:
Gyula Lakos ( Budapest ): " How does a 2x2 matrix distort something? "



Past Attractions for the Spring Semester 2017



April 27:
Dávid Szeghy ( Budapest ): " Mean curvature stream and isoperimetric inequalities II "
April 20:
Dávid Szeghy ( Budapest ): " Mean curvature stream and isoperimetric inequalities I "
April 6:
Károly Böröczky ( Budapest ): " Locally homogeneous incongruent packings of circles in the plane "
March 23:
Balázs Csikós ( Budapest ): " Harmonic manifolds and tubes around the geodesic lines II "
March 2:
Gábor Etesi ( Budapest ): " On the complex structure of the 6--dimensional sphere "
February 23:
Balázs Csikós ( Budapest ): " Harmonic manifolds and tubes around the geodesic lines I "
February 16:
Márton Naszódi ( Budapest ): " Approximation of polytopes in the Banach--Mazur metric "



Past Attractions for the Fall Semester 2015



October 15:
Márton Naszódi ( Budapest ): " Proveing a conjecture of Barany, Katchalski and Pach "
September 24:
Dávid Szeghy ( Budapest ): " The leaping of the differentiability of horizons "



Past Attractions for the Spring Semester 2015



April 16:
Zoltán Muzsnay ( Debrecen ): " Results on the holonomy of Finsler-spaces "



Past Attractions for the Fall Semester 2014



November 13:
Robert Wolak ( Krakow ): " Cohomology theories for Riemannian foliations "
October 9:
Gábor Etesi ( Budapest ): " A modular functor determined by C*-algebra representations "



Past Attractions for the Spring Semester 2014



May 15:
Károly Bezdek ( Calgary, Budapest ): " Contact numbers: old and new "
April 24:
Karla Počkaj ( Primorska ): " C^1 Hermite interpolation with spatial PH cubic biarcs and a fully data-dependent criterion for free angles selection "
April 10:
Károly Böröczky ( Budapest ): " About the 12-neighboring sphere-packing of László Fejes Tóth II "
April 3:
Károly Böröczky ( Budapest ): " About the 12-neighboring sphere-packing of László Fejes Tóth I "
February 27:
Rolf Schneider ( Freiburg ) " Convex bodies of constant width and diametric completions "



Past Attractions for the Fall Semester 2013



September 12:
Gyula Lakos ( Budapest ): " (Fermionic) quantum orthogonalization "



Past Attractions for the Spring Semester 2013



May 23:
Károly Bezdek ( Calgary ): " On some generalizations of Tarski's plank problem "
May 16:
Ademir Hujdurovic ( Primorska ): " Pentavalent symmetric bicirculants "
May 2:
László Fehér ( Szeged ): " Action-angle variables of the Toda molecule from the viewpoint of Hamiltonian reduction "
April 25:
László Fehér ( Budapest ): " Counting problems in real algebraic geometry "
April 4:
Endre Makai ( Budapest ): " The number of pairs of strictly antipodal points "
March 21:
Zsolt Lángi ( Budapest ): " The robustness of convex bodies "
March 14:
Szilárd Szabó ( Budapest ): " About the modulus-spaces of 2-order connexions on the Riemann-sphere "
March 7:
Dávid Szeghy ( Budapest ): " About the properties of infinitezimal orbit types "
February 28:
Gábor Etesi ( Budapest ): " An energy formula related to Yang-Mills instantons over ALF-manifolds "



Past Attractions for the Fall Semester 2012



December 6:
Márton Horváth ( Budapest ): " A characterization of spaces of constant curvature by minimum covering radius of triangles "
November 29:
András Némethi ( Budapest ): " About the polynomials of Ehrhart polytopes and the invariants of Seiberg-Witten 3-manifolds "
November 22:
Károly Böröczky Jr. ( Budapest ): " A variation of the Minkowski problem and the logarithmic Brunn-Minkowski inequality "
November 15:
Márton Naszódi ( Budapest ): " Spindle starshaped sets "
November 8:
György Kiss ( Budapest ): " Rainbow-free colorings of PG(n,q) "
October 4:
Zoltán Muzsnay ( Debrecen ): " New results on the holonomy of Finsler-spaces of constant curvature "
September 27:
Christian Rubio ( Mexico ): " Geometric achromatic and pseudochromatic index "
September 20:
Imre Bárány ( Budapest ): " Tensors and Octaeders "



Past Attractions for the Spring Semester 2012



May 24:
Károly Bezdek ( Calgary, Budapest ): " On global and local rigidity of ball-polyhedra "
May 17:
Béla Uhrin ( Budapest ): " About the mystery of the equilateral triangle "
May 3:
Zsolt Lángi ( Budapest ): " About the generalization of a Borsuk problem "
April 26:
Márton Naszódi ( Budapest ): " About the rigidity of spherical polyeders "
April 19:
Konrad Schöbel ( Jena ): " The Variety of Integrable Killing Tensors on the 3-Sphere "
April 12:
Szilárd Szabó ( Budapest ): " About the virtual singularities of logarithmic connexions "
March 29:
Márton Naszódi ( Budapest ): " About the rigidity of spherical polyeders "
March 22:
László Fehér ( Budapest ): " The self-duality transformation of Ruijsenaars as the simplexomorphism of a class of maps "
March 8:
Balázs Csikós ( Budapest ): " A characterisation of harmonic spaces "
March 1:
Mihály Hujter ( Budapest ): " Is there necessary a fifth colour? - About the graph-coloring results of György Hajós based on geometry and the history of his conjectures "
February 16:
Zoltán Szilasi ( Debrecen ): " Some closureing property of projective planes "




Past Attractions for the Fall Semester 2011



December 15:
László Verhóczki ( Budapest ): " Parallel submanyfolds in Riemannian spaces of constant curvature "
December 1:
Gábor Fejes Tóth ( Budapest ): " Short pathes between spherical obstacles "
November 24:
István Rácz ( Budapest ): " The topological properties of two-codimension strictly stable spacelike surfaces "
November 10:
Géza Kós ( Budapest ): " Roving not only in Euclidean spaces "
October 27:
Horst Martini ( Germany ): " Problems from Convexity in Minkowski spaces "
October 20:
Nataliya Daurtseva ( Russia ): " Invariant almost complex structures on S^{2n+1} x S^{2p+1} "
October 13:
András Némethi ( Budapest ): " Gridpoint cohomology II "
October 6:
András Némethi ( Budapest ): " Gridpoint cohomology I "
September 22:
Dávid Szeghy ( Budapest ): " About the non-normalizable infinitezimal orbit types of Lorentz-manyfolds "
September 15:
Gyula Lakos ( Budapest ): " About the geometric aspects of linear algebra "



Past Attractions for the Spring Semester 2011



May 19:
Jerry L. Kazdan ( Pennsylvania ): " Application of the Ricci Flow to Prove Pinching Theorems "
May 5:
Károly Bezdek ( Budapest ): " About the contact numbers of sphere packings "
April 28:
Gábor Kertész ( Budapest ): " Covering the surface of a sphere by given diameter sets - proving a conjecture of Aladár Heppes "
April 14:
Vladimir Matveev ( Jena ): " Partially smooth Finsler metrics and Binet-Legendre Riemannian metric "
April 7:
Zsolt Lángi ( Budapest ): " Examining the balance positions of convex bodies "
March 31:
Béla Uhrin ( Budapest ): " Discrete convexity "
March 17:
Károly Böröczky ( Budapest ): " Transversals of congruent circles in E^2 "
March 10:
Miklós Pálfia ( Budapest ): " Classification of affine means of matrices "
March 3:
Gábor Etesi ( Budapest ): " About the existence of complex structures on 6-dim spheres "



Past Attractions for the Fall Semester 2010



December 9:
Zoltán Muzsnay ( Debrecen ): " New results on the holonomy of Finsler spaces "
December 2:
Gábor Moussong ( Budapest ): " Topological circle-decompositions of surfaces "
November 25:
Béla Uhrin ( Budapest ): " Discrete geometric number theory "
November 18:
Márton Naszódi ( Budapest ): " Questions around the illumination problem "
November 11:
Balázs Csikós, Márton Horváth ( Budapest ): " About the volume of the intersection of geodetic spheres II "
November 4:
Balázs Csikós, Márton Horváth ( Budapest ): " About the volume of the intersection of geodetic spheres I "
October 14:
Gábor Etesi ( Budapest ): " S-duality in Abelian Yang-Mills theories II. "
October 7:
Gábor Etesi ( Budapest ): " S-duality in Abelian Yang-Mills theories I. "
September 23:
Dávid Szeghy ( Budapest ): " The Maslov index for semi-Riemannian manyfolds (2) "





Past Attractions for the Spring Semester 2010



May 6:
Márton Naszódi ( Budapest ): " The intersection of the shiftings of convex bodies - a generalization of spheric-polyeders "
April 29:
Miklós Pálfia ( Budapest ): " Affine symmetric spaces and means of matrices "
April 22:
Dávid Szeghy ( Budapest ): " The Maslov-index and it's application to focal and conjugate points "
April 15:
Jenő Szirmai ( Budapest ): " Special horospheric fillings of famous tilings in hyperbolic space "
March 18:
Ákos G. Horváth ( Budapest ): " Geometries defined by semi-indefinit scalar product "
March 4:
Lajos Tamássy ( Debrecen ): " The isometries of Finsler-spaces "
February 25:
Gábor Kertész ( Budapest ): " Maximal-area jointed quadrangles on IE^2, IH^2 and S^2 "
February 18:
Richárd Rimányi ( Budapest ): " Geometry theorems of secondary schools from the viewpoint of equivariance "
February 11:
László Szabados ( Budapest ): " The pp-wave solutions of general theory of relativity and the Penrose-limes "




Past Attractions for the Fall Semester 2009



December 17:
Endre Makai ( Budapest ): " About the problem of volume-product "
December 3:
László Fehér ( Budapest and Szeged ): " Poisson-Lie interpretation of trigonometric Ruijsenaars duality "
November 26:
Gábor Etesi (Budapest): " SU(2) instanton-modulus spaces above asymptotically flat 4-manyfolds "
November 19:
Sándor Kristály (Kolozsvár): " Metric projections and Nash-balance-points in Riemann-Finsler-manyfolds "
November 5:
György Kiss (Budapest, Hungary): " About some generalizations of the illumination problem "
October 22:
Péter Nagy (Debrecen, Hungary): " Finsler spaces of which the holonomy group differs from the one of Riemannian spaces - II. "
October 15:
Zoltán Muzsnay (Debrecen, Hungary): " Finsler spaces of which the holonomy group differs from the one of Riemannian spaces - I. "
October 8:
Márton Naszódi (Budapest, Hungary): " The maximal distance of convex sets in R^n - II. "
October 1:
Márton Naszódi (Budapest, Hungary): " The maximal distance of convex sets in R^n - I. "
September 17:
Dávid Szeghy (Budapest, Hungary): " A proof of an infinitesimal orbit type theorem "
September 11:
Kojun Abe (Shinshu University, Japan): " The first holonomy of the group of equivariant
diffeomorphisms and its application "





Past Attractions for the Spring Semester 2009



May 14:
László Fehér (Budapest and Szeged, Hungary): " On the duality between the hyperbolic Sutherland
and the rational Ruijsenaars-Schneider models "
April 30:
Aladár Heppes (Budapest, Hungary): " About a possible way of improveing the T(5)-theorem of Danzer "
April 23:
Cenap Özel (Bolu, Turkey): " Divided power algebras, Schubert calculus and
complex cobordism of Hilbert manifolds "
April 2:
Károly Böröczky Jr. (Budapest, Hungary): " The Prekopa-Leindler inequality in the view of a geometer "
March 19:
László Verhóczki (Budapest, Hungary): " About the Funk transformation in compact symmetric spaces "
March 12:
Károly Böröczky (Budapest, Hungary): " About the transversals of circles - III. "
March 5:
Károly Böröczky (Budapest, Hungary): " About the transversals of circles - II. "
February 26:
Károly Böröczky (Budapest, Hungary): " About the transversals of circles - I. "
February 19:
Béla Uhrin (Budapest, Hungary): " About inconsistent linear systems of inequalities "
February 12:
György Kiss (Budapest, Hungary): " Sudoku and finite geometries "



Past Attractions for the Fall Semester 2008


December 11:
István Lénárt (Budapest, Hungary): " Some results connected with the theory of projective spheres "
December 4:
Gabriella Pluhár (Budapest, Hungary): " Islands in triangular grids and in higher dimensions "
November 27:
István Rácz (Budapest, Hungary): " On the topoligical properties of black holes in the various geometrised theories of gravity - II "
November 20:
István Rácz (Budapest, Hungary): " On the topoligical properties of black holes in the various geometrised theories of gravity - I "
November 6:
János Szenthe (Budapest, Hungary): " On the isometries of Riemannian manifolds "
October 16:
Balázs Csikós (Budapest, Hungary): " Spherical Polytopes of Critical Volume with Given Insphere "
October 2:
Dénes PETZ (Budapest, Hungary): " Riemannian geometry on positive definit matrices "



Past Attractions for the Spring Semester 2008



April 3:
Dávid Szeghy (Budapest, Hungary): " About infinitesimal principal orbit-type theorems "
March 27:
Vladimir Matveev (Jena, Germany): " Polyhedral 3-manifolds of nonnegative curvature "
March 13:
Gyula Lakos (Budapest, Hungary): " On the H-ring structure of infinite Grassmann-manyfolds "
March 6:
Gábor Moussong (Budapest, Hungary): " Grid-cubes "
February 28:
Imre Bárány (Budapest, Hungary): " About the convex-hull of grid-points "
February 21:
Balázs Csikós (Budapest, Hungary): "About vector-valued Schlafli-formulae"
February 14:
György Kiss (Budapest, Hungary): "About the Röntgen-number of convex bodies"



Past Attractions for the Fall Semester 2007



December 13:
Károly Böröczky (Budapest, Hungary): "About the stability of affine isoperimetric and Blaschke-Santalo inequalities"
December 6:
Károly Böröczky (Budapest, Hungary): "About the affine isoperimetric and the Blaschke-Santalo inequalities"
November 29:
János Szenthe (Budapest, Hungary): " On the orbits of the isometry groups of Lorentz-manyfolds II "
November 22:
János Szenthe (Budapest, Hungary): " On the orbits of the isometry groups of Lorentz-manyfolds I "
November 8:
Gábor Kertész (Budapest, Hungary): "An absolute proof of an isoperimetric problem   -   II"
October 25:
Gábor Kertész (Budapest, Hungary): "An absolute proof of an isoperimetric problem   -   I"
October 18:
Károly Böröczky (Budapest, Hungary): "About circle coverings on hyperbolic plane (calculation details)   -   II"
October 11:
Gudlaugur Thorbergsson (Köln, Germany): "Singular Riemannian Foliations"
October 4:
Károly Böröczky (Budapest, Hungary): "About circle coverings on hyperbolic plane (calculation details)   -   I"




Past Attractions for the Spring Semester 2007



July 26:
10:30-12:00: Alexander LITVAK (University of Alberta - Canada): " Vertex index of convex bodies and asymmetry of convex polytopes "
12:30-14:00: Henry COHN (Microsoft Res. and Univ. of Washington - USA): " Energy Minimization "
May 10:
László Fehér (Budapest and Szeged, Hungary): "Hamiltonian reductions of the free particle on a simple Lie group to (spin) Calogero type integrable models"
April 26:
György Kiss (Budapest, Hungary): "About the finite geometry constructions of extremal graphs"
April 19:
Dávid Szeghy (Budapest, Hungary): "About the changes of the order of differentiability of horizons along the generators"
April 12:
András Némethi (Budapest, Hungary): "Algebraic plane curves"
March 8:
Gábor Gévay (Szeged, Hungary): "Hamiltonicity of Wythoff polytopes"
March 1:
Rolf Schneider (Univ. Freiburg, Germany): "Sums of congruent convex bodies"
February 22:
Károly Böröczky Jr. (Budapest, Hungary): "About the number of facets of lattice polytopes"



Past Attractions for the Fall Semester 2006


November 30:
Balázs Bárány (Budapest, Hungary): "About the geodetics of Gödel-univers"
November 23:
Kálmán Kövári, Dávid Szeghy (Budapest, Hungary): "A more geometrical proof of the differentiability of horisonts"
November 16:
Károly Böröczky (Budapest, Hungary): "Circle covering on hyperbolic plane"
October 12:
Balázs Csikós (Budapest, Hungary): "About the rigidity of regular bicycle-polygons"
October 5:
Lajos Szilassi (Szeged, Hungary): "The Szilassi-polyeder and its history"
September 28:
Christian Richter (Jena, Germany): "Disjoint affine tilings of convex sets"



Past Attractions for the Spring Semester 2006


June 28 (Wednesday!) - Extra Seminar!!:
Károly Bezdek (Budapest, Hungary): "The illumination problem and its generalizations"
May 4:
Mihály Hujter (Budapest, Hungary): "About the five-color theorem and four-color conjecture concerning Borsuk problems"
April 27:
Attila Csáky (Budapest, Hungary): "Butterfly theorems in the hyperbolic plane"
April 20:
József Szilasi (Debrecen, Hungary): "Ehresmann-connexions and good metric derivatives"
April 6:
Gyula Lakos (Budapest, Hungary): "About the Mathai-Quillen formula"
March 30:
jnr. Károly Böröczky (Budapest, Hungary): "About the minimal volume of polyhedra written into a spherical shell"
March 23:
László Verhóczki (Budapest, Hungary): "Tubular structures of compact symmetric spaces of type E6/K"
March 16:
László Verhóczki (Budapest, Hungary): "Hyperpolar isometric actions on exceptional compact symmetric spaces"
March 9:
Károly Böröczky (Budapest, Hungary): "On 12-neigbour sphere packings"
March 2:
Balázs Csikós (Budapest, Hungary): "Bicycle-trace geometry"
February 23:
György Kiss (Budapest, Hungary): "Semiovals and factorizations of groups"
February 16:
Bácsó Sándor (Debrecen, Hungary): "About the rectificationability of solutions of second order differential equations"



Past Attractions for the Fall Semester 2005


December 1:
Szilvia Homolya (Miskolc, Hungary): "Two-step homogeneous nilmanifolds"
November 24:
Péter Nagy (Debrecen, Hungary): "On the isomorphy classes of 1-dimensional differentiable loops"
November 17:
János Kincses (Szeged, Hungary): "Defineing a convex set on the base of its intersections"
October 13:
Dávid Szeghy (Budapest, Hungary): "The isometric effect of a compact Lie-group on Lorentz-manyfolds"
October 6:
Balázs Csikós (Budapest, Hungary): "The Kneser-Poulsen conjecture in elliptical space"
September 29:
Zoltán Muzsnay (Debrecen, Hungary): "Variational differential equations of second order and their applications in geometry"



Past Attractions for the Spring Semester 2005


June 24 (Friday!!):
Károly Bezdek(Budapest, Hungary): "Spherical polyeders"
May 19:
Zoltán Muzsnay (Debrecen, Hungary): "Variational differential equations of second order and their applications in geometry"
May 5:
János Szenthe (Budapest, Hungary): "On the isometry groups of Lorentz-manyfolds"
April 21:
Balázs Csikós (Budapest, Hungary): "On the transversals of superdisjunct and weakly overlapping congruent circle systems"
April 14:
Károly Böröczky (Budapest, Hungary): "On transversals"
April 7:
György Kiss (Budapest, Hungary):
"Semiovals"
March 31:
Csaba Vincze (Debrecen, Hungary):
"An existance theorem of Wagner-manyfolds"
March 3:
Gábor Etesi (Budapest, Hungary):
"A theorem on integrals connecting to almost-complex manyfolds"
February 24:
László Verhóczki (Budapest, Hungary):
"Volumes of principal orbits of isotropy
subgroups in compact symmetric spaces"
February 17:
László Kozma (Debrecen, Hungary): "Busemann hyperbolicity in Finsler spaces"



Past Attractions for the Fall Semester 2004


December 9:
János Szenthe (Budapest, Hungary): "A theorem of G. D. Birkhoff in Lorenz-geometry"
December 2:
Robert Szöke (Budapest, Hungary): "Weyl-group equivariant maps"
November 18:
Gyula Lakos (Budapest, Hungary): "Smooth classifying spaces"
November 11:
Gábor Moussong (Budapest, Hungary): "The de Sitter-sphere"
October 21:
Dávid Szeghy (Budapest, Hungary): "Conjugated points in Lorentz-manyfolds; the example of Helfer"
October 7:
Károly Böröczky Jr. (Budapest, Hungary): "On the density of hyperbolic packings (III)"
September 30:
Károly Böröczky Jr. (Budapest, Hungary): "On the density of hyperbolic packings (II)"
September 23:
Károly Böröczky Jr. (Budapest, Hungary): "On the density of hyperbolic packings (I)"



Past Attractions for the Spring Semester 2004


April 29:
Gábor Moussong (Budapest, Hungary): "Questions about topological rigidity (II)"
April 22:
Gábor Moussong (Budapest, Hungary): "Questions about topological rigidity (I)"
April 15:
Dávid Szeghy (Budapest, Hungary): "Conjugated points in Lorenz-geometry"
April 1:
Tamás Szönyi (Budapest, Hungary): "How many different directions are determined by the graph of a function on finit plane"
March 25:
János Szenthe (Budapest, Hungary): "The transversal subsets of group actions"
March 4:
Károly Böröczky (Budapest, Hungary): "About the parallel supporting planes of polyeders (II)"
February 26:
Károly Böröczky (Budapest, Hungary): "About the parallel supporting planes of polyeders (I)"



Past Attractions for the Fall Semester 2003


December 17:
László András (Budapest, Hungary): "A theorem on the existance of parallel volumetric forms"
December 10:
László Verhóczki (Budapest, Hungary): "On the tubular structure of the exceptional G2 and F4 compact Lie-groups"
December 3:
Balázs Csikós (Budapest, Hungary): "Open questions about the Kneser-Poulsen problem"
November 26:
Endre Szabó (Budapest, Hungary): "About the resoults of Gyula Szökefalvi Nagy in algebraic geometry"
November 19:
János Szenthe (Budapest, Hungary): "About the resoults of Gyula Szökefalvi Nagy in the theory of finit order curves"
November 11, Tuesday, at 16:00-... (!!!):
Prof. Geoffrey K. MARTIN (University of Toledo, USA): "Accelerated expansion, inflation and the trace inequality"
November 5:
András Szenes (Budapest, Hungary): "Equivariant integrals and the Bethe-Ansatz"
October 15:
Károly Böröczky (Budapest, Hungary): "The Thammes-problem"
October 8:
István Talata (Budapest, Hungary): "On the generalized touching numbers of cross-polytopes"



Past Attractions for the Spring Semester 2003


May 15:
János Szenthe (Budapest, Hungary): "Spheresymmetric spacetimes"
April 10:
György Kiss (Budapest, Hungary): "How should we organize a soccer championship?"
April 3:
Károly Böröczky (Budapest, Hungary): "Compareing of the structures of the hyperbolic geometries of Bólyai and of Lobachewsky"
Marc 27:
Wu Yi Hsiang (Hong Kong): "Sphere packing problems in dimensions higher than 3"
Marc 20:
András Juhász (Budapest, Hungary): "On the regular homotopy classes of locally generic maps"
Marc 6:
Dávid Szeghy (Budapest, Hungary): "On generalized Robertson-Walker spacetimes II"
February 27:
Dávid Szeghy (Budapest, Hungary): "On generalized Robertson-Walker spacetimes I"



Past Attractions for the Fall Semester 2002


December 12:
Frank Morgan (Williamstown, USA): "Soap Bubbles and Mathematics"
December 5:
Viktor Bodi (Debrecen, Hungary): "Generalised crystal groups"
November 21:
Gábor Etesi (Budapest, Hungary): "Yang-Mills instantons over gravity instantons (III)"
November 14:
Gábor Etesi (Budapest, Hungary): "Yang-Mills instantons over gravity instantons (II)"
November 7:
Gábor Etesi (Budapest, Hungary): "Yang-Mills instantons over gravity instantons (I)"
October 31:
László Verhóczki (Budapest, Hungary): "Harmonic and minimal fields of unit vectors on symmetric Riemann spaces (II)"
October 24:
László Verhóczki (Budapest, Hungary): "Harmonic and minimal fields of unit vectors on symmetric Riemann spaces (I)"
October 17:
Balázs Csikós (Budapest, Hungary): "Schlafli-type formulas and their applications for Kneser-conjecture"



Past Attractions for the Spring Semester 2002


June 27:
András Prékopa (Rutgers Univ./ELTE, USA/Hungary): "Bounding measures of Boolean functions of sets by the use of discrete moment problem"
June 13:
Robert Connelly (Cornell Univ., Ithaca, USA): "Applications of tensegrities to geometry"
May 30:
Robert Connelly (Cornell Univ., Ithaca, USA): "Locked chains in the plane"
May 23:
Robert Connelly (Cornell Univ., Ithaca, USA): "Poulsen conjecture - an introduction"
May 7 (Tuesday):
LOCATION: Technical Univ. of Budapest,
BME, Building "H", 3rd fl., 306 lr.:
Jenő Szirmai (Budapest, Hungary): "Hyperbolic space filling by Lambert-cubes"
April 23 (Tuesday):
LOCATION: Technical Univ. of Budapest,
BME, Building "H", 3rd fl., 306 lr.:
Ákos G. Horváth (Budapest, Hungary): "Normaltransversals in hyperbolic space"
April 18:
Attila Por (Budapest, Hungary): "Edge-antipodal polyeders"
April 9 (Tuesday!!!):
LOCATION: Technical Univ. of Budapest,
BME, Building "H", 3rd fl., 306 lr. (!!!):
Ferenc Fodor (Szeged, Hungary): "Densest packing with 13 congruent circles"
April 4:
Aladár Heppes (Budapest, Hungary): "Packings with incongruent circles II"
Marc 21:
Aladár Heppes (Budapest, Hungary): "Packings with incongruent circles I"
Marc 12 (Tuesday!!!):
LOCATION: Technical Univ. of Budapest,
BME, Building "H", 3rd fl., 306 lr. (!!!):
Emil Molnár (Budapest, Hungary): "Minimal surfaces, generalizations of Schwarz-type examples"
Marc 7:
Károly Bezdek (Budapest, Hungary): "On the contact numbers of finite sphere packings"
February 28:
István Talata (Michigan Univ., USA): "On the combinatorical structure of sphere packings of L_p spaces"



Past Attractions for the Fall Semester 2001


November 22:
Christian Richter (Jena, Germany): "Congruence by dissection of topological disks
- An elementary approach to Tarski's circle squaring problem"
November 15:
Borbála Farkas (Budapest, Hungary): "The Dekster's definition of the width of spherical sets"
October 25:
János Szenthe (Budapest, Hungary): "The Dekster's definition of the width of sets in hyperbolic space"



Past Attractions for the Spring Semester 2001


June 15:
István Talata (Michigan Univ., USA): "On Hadwiger numbers of strictly convex bodies"
June 6 (Thursday!!!):
Tibor Jordán (Budapest, Hungary): "A proof of Connelly's conjecture on 3-connected generic cycles"
June 1:
Robert Connelly (Cornell Univ., Ithaca, USA): "Unique generic graph embeddings"
May 25:
Robert Connelly (Cornell Univ., Ithaca, USA): "How to open a carpenter's rule in the plane"
May 18:
Michele Mulazzani (Univ. Bologna, Italy): "Strongly-cyclic branched coverings of (1,1)-knots
and the mapping class group of the twice punctured torus"
May 4:
Gábor Kertész (Budapest, Hungary): "A new theorem on super-additivity II"
April 27:
Gábor Kertész (Budapest, Hungary): "A new theorem on super-additivity I"
April 19 (Thursday!!!):
Károly Bezdek (Budapest, Hungary): "The illumination problem in spherical space"
April 6:
Balázs Csikós (Budapest, Hungary): "Small convex polytopes with many vertices and long edges"
March 22 (Thursday!!!):
Károly Bezdek (Budapest, Hungary): "On the maximum number of thouching pairs in a
finite packing of translates of a convex body II"
March 8 (Thursday!!!):
Károly Bezdek (Budapest, Hungary): "On the maximum number of thouching pairs in a
finite packing of translates of a convex body I"
March 2:
Gábor Moussong (Budapest, Hungary): "On the geometrization conjecture of Thurston"
February 23:
Aladár Heppes (Budapest, Hungary): "On multiple saturations in lattice packings II."
February 16:
Aladár Heppes (Budapest, Hungary): "On multiple saturations in lattice packings I."
February 9:
Péter Nagy (Debrecen, Hungary): "Loops as sections in groups and their geometry"



Past Attractions for the Fall Semester 2000


December 20 (Wednesday!!!):
Mihály Hujter (Miskolc, Hungary): "Geometry of the Bethlehem Star and other astronomical- geometrical questions related to the calendars"
(12:00-14:00 !!!)
December 8:
László Verhóczki (Budapest, Hungary): "Computing the volumes of symmetric spaces via isometric group actions"
December 1:
Zoltán Füredi (Budapest, Hungary): "On the combinatorial structure of finite pointsets"
November 17:
Károly Bezdek (Budapest, Hungary): "On some isoperimetric properties of Voronoi polytopes"
November 3:
Peter Brass (Berlin, Germany): "Combinatorial geometry problems for pattern recognation"
October 25 (Wednesday!!!):
Peter Brass (Berlin, Germany): "Problems on approximation by polygons"
(12:00-13:15 !!!)
October 20:
Károly Böröczky (Budapest, Hungary): "On the density of circle and sphere packings"
October 11 (Wednesday!!!):
Heiko Harborth (Braunschweig, Germany): "Some Eszter Klein Problems"
(12:00-13:15 !!!)
October 6:
Károly Bezdek (Budapest, Hungary): "On a stronger form of Rogers's lemma"
September 27 (Wednesday!!!):
Tudor Zamfirescu (Dortmund, Germany): "Around the cut locus"
(12:00-13:15 !!!)
September 22:
Károly Bezdek (Budapest, Hungary): "On the rigidity of convex polyhedra"



Past Attractions for the Spring Semester 2000


May 17:
Zsolt Lángi (Budapest, Hungary): "On the side lengths of hexagons"
and
Gábor Horváth (Budapest, Hungary): "Minkowski circle arrangements"
(10:15-12 AM !!!)
May 10:
József Korándi-Márton Naszódi (Budapest, Hungary): "Generalized tetrahedra"
(10:30-12 AM !!!)
May 3:
Gyula Nagy (Budapest, Hungary): "Rigidity of cubic lattices"
April 26:
Csaba Mengyán-Csaba Szántó (Budapest, Hungary): "Borsuk's problem in Minkowski space"
April 12:
Károly Bezdek (Budapest, Hungary): "On the Radon number of lattices"
April 5:
John Francis (Washington, USA): "Extensions on the Erdõs-Szekeres problem"
March 22:
Grigoriy Blekherman (New York, USA): "Blaschke-Lebesgue's theorem on the sphere"
March 8:
Aart Blokhuis (Eindhoven, Holland): "On the size of regular polygons in R^n with the l_infinite-norm"
March 1:
Grigoriy Blekherman (New York, USA): "Danzer-Grünbaum's theorem revisited"



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