Home /  Triangulations of Point Sets: Applications, Structures, Algorithms

Summer Graduate School

Triangulations of Point Sets: Applications, Structures, Algorithms July 21, 2003 - July 31, 2003
Parent Program: --
Organizers Jesús A. De Loera, Jörg Rambau, and Francisco Santos
Description Please note: MSRI's Summer Graduate Programs are open only to students nominated by MSRI's Academic Sponsor universities.

Goals:
One of the most useful techniques in Discrete and Computational Geometry is to decompose a region of space (usually a polyhedron) into simplices, that is to say, to triangulate it. When the set of points allowed as vertices is fixed in advance, we say we are triangulating a point configuration, or a point set. On the side of applications, triangulating a geometric domain which we intend to study (whatever its dimension) is a standard procedure for computing its volume, integrating or solving differential equations, interpolation, surface reconstruction from a discrete sampling, fixed-point calculations, etc.. Simplicial or triangulated objects are classical in topology, and they have revived as fundamental techniques in current research due in good part to the availability of tools for effective, concrete computations. In algebraic geometry, the so-called toric varieties and part of elimination theory can be reformulated in terms of polytopes and polyhedra, and there is a quite exact dictionary between algebraic properties of the varieties and properties of special triangulations.

The main goal of this school is to introduce graduate students to triangulations of point sets. We plan to stress the rich connections to algebraic geometry, topology, geometric algorithms, and combinatorics. Topics will include the study of topological structures on the set of all triangulations of a point set (flip graphs, secondary polytope, Baues posets), connections of these structures to other fields (computer science, optimization, algebraic geometry). We will discuss many classical examples such as triangulations of cyclic polytopes and cubes. The course will discuss the most recent advances such as the construction of triangulations without bistellar flips, the Generalized Baues Problem, enumeration and optimization problems (e.g. optimal triangulations of cubes). Other themes that will be discussed include:

  • Results indicating how small we can hope our triangulation to be (lower or upper bounds to the sizes of triangulations, for example)
  • Algorithms leading to an optimal triangulation, or a good approximation of it, together with an analysis of how long it will take us to obtain it
  • Theoretical results of how good we can expect the algorithms in the previous paragraph to be. For example, computing the minimal triangulation of a 3-dimensional polytope is NP-complete
  • The problem of enumerating all the possible triangulations of a point set

The school will allow students to gain a perspective of cross-disciplinary aspects of the topic from experts and provide them with the opportunity to explore new research topics.

Structure:
The summer school will have two 90-minute lectures each day in the morning and early afternoon. Late afternoon workshops and laboratories will be based around group explorations of research oriented questions. We also hope to complete each week with a couple of invited lecturers. These will be distinguished experts on special hot topics (to be announced). Students will be expected to have a good background in linear algebra. Knowledge in linear programming and/or computational geometry is useful but is not required. The course will closely follow a draft from a forthcoming book on the topic.

This program is partially sponsored by MSRI's Academic Sponsors.
Keywords and Mathematics Subject Classification (MSC)
Primary Mathematics Subject Classification No Primary AMS MSC
Secondary Mathematics Subject Classification No Secondary AMS MSC
Schedule, Notes/Handouts & Videos
Show Schedule, Notes/Handouts & Videos
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Jul 21, 2003
Monday
08:00 AM - 05:00 PM
  Unfriendly Spaces of Triangulations, I
Francisco Santos
08:00 AM - 05:00 PM
  Triangulations and Lattice Polytopes
Jesus De Loera
08:00 AM - 05:00 PM
  The Cayley Trick
Francisco Santos
08:00 AM - 05:00 PM
  Fiber Polytopes
Joerg Rambau
08:00 AM - 05:00 PM
  Glass and Geometry
Cliff Stall
08:00 AM - 05:00 PM
  Triangulations of Point Sets
Bernd Sturmfels
08:00 AM - 05:00 PM
  Enumeration in the Space of Triangulations, II
Joerg Rambau
08:00 AM - 05:00 PM
  Enumeration in the Space of Triangulations, I
Joerg Rambau
08:00 AM - 05:00 PM
  Lower Bounds for Minimal Triangulations of Cubes
Francis Su
08:00 AM - 05:00 PM
  Optimization in the Space of Triangulations, II
Jesus De Loera
08:00 AM - 05:00 PM
  Optimization in the Space of Triangulations, I
Jesus De Loera
08:00 AM - 05:00 PM
  Unfriendly Spaces of Triangulations, II
Francisco Santos
08:00 AM - 05:00 PM
  Motivation and Fundamental Notions, I
Francisco Santos
08:00 AM - 05:00 PM
  A Friendly Space of Triangulations: Cyclic Polytopes, II
Joerg Rambau
08:00 AM - 05:00 PM
  A Friendly Space of Triangulations: Cyclic Polytopes, I
Joerg Rambau
08:00 AM - 05:00 PM
  Nonregular Triangulations, II
Francisco Santos
08:00 AM - 05:00 PM
  Nonregular Triangulations, I
Francisco Santos
08:00 AM - 05:00 PM
  Regular Triangulations and Secondary Polytopes, II
Joerg Rambau
08:00 AM - 05:00 PM
  Regular Triangulations and Secondary Polytopes, I
Joerg Rambau
08:00 AM - 05:00 PM
  Delauny Triangulations and Relations to Computational Geometry
Jonathan Shewchuk
08:00 AM - 05:00 PM
  Life in Two Dimensions, II
Jesus De Loera
08:00 AM - 05:00 PM
  Life in Two Dimensions, I
Jesus De Loera
08:00 AM - 05:00 PM
  Motivation and Fundamental Notions, II
Francisco Santos