Browsing 2  Snapshots of Modern Mathematics from Oberwolfach by Snapshot Mathematical Subject "Discrete Mathematics and Foundations"
Now showing items 120 of 23

Aperiodic Order and Spectral Properties
[SNAP2017003EN] (Mathematisches Forschungsinstitut Oberwolfach, 20170914)Periodic structures like a typical tiled kitchen floor or the arrangement of carbon atoms in a diamond crystal certainly possess a high degree of order. But what is order without periodicity? In this snapshot, we are ... 
Computing with symmetries
[SNAP2018003EN] (Mathematisches Forschungsinstitut Oberwolfach, 20180306)Group theory is the study of symmetry, and has many applications both within and outside mathematics. In this snapshot, we give a brief introduction to symmetries, and how to compute with them. 
Domino tilings of the Aztec diamond
[SNAP2015016EN] (Mathematisches Forschungsinstitut Oberwolfach, 2015)Imagine you have a cutout from a piece of squared paper and a pile of dominoes, each of which can cover exactly two squares of the squared paper. How many different ways are there to cover the entire paper cutout with ... 
Finite geometries: pure mathematics close to applications
[SNAP2021010EN] (Mathematisches Forschungsinstitut Oberwolfach, 20210922)The research field of finite geometries investigates structures with a finite number of objects. Classical examples include vector spaces, projective spaces, and affine spaces over finite fields. Although many of these ... 
Footballs and donuts in four dimensions
[SNAP2016012EN] (Mathematisches Forschungsinstitut Oberwolfach, 2016)In this snapshot, we explore connections between the mathematical areas of counting and geometry by studying objects called simplicial complexes. We begin by exploring many familiar objects in our three dimensional world ... 
Formation Control and Rigidity Theory
[SNAP2019017EN] (Mathematisches Forschungsinstitut Oberwolfach, 20191211)Formation control is one of the fundamental coordination tasks for teams of autonomous vehicles. Autonomous formations are used in applications ranging from searchandrescue operations to deep space exploration, with ... 
Friezes and tilings
[SNAP2015004EN] (Mathematisches Forschungsinstitut Oberwolfach, 2015)Friezes have occured as architectural ornaments for many centuries. In this snapshot, we consider the mathematical analogue of friezes as introduced in the 1970s by Conway and Coxeter. Recently, infinite versions of such ... 
From the dollar game to the RiemannRoch Theorem
[SNAP2021001EN] (Mathematisches Forschungsinstitut Oberwolfach, 20210223)What is the dollar game? What can you do to win it? Can you always win it? In this snapshot you will find answers to these questions as well as several of the mathematical surprises that lurk in the background, including ... 
The Geometry of Fair Division
[SNAP2023007EN] (Mathematisches Forschungsinstitut Oberwolfach, 20231230)How can we fairly divide a necklace with various types of beads? We use this problem as a motivating example to explain how geometry naturally appears in solutions of nongeometric problems. The strategy we develop to solve ... 
Geproci Sets: a New Perspective in Algebraic Geometry
[SNAP2023008EN] (Mathematisches Forschungsinstitut Oberwolfach, 20231230)Geproci sets arise from applying the perspective of inverse scattering problems to algebraic geometry. Analogous to the reconstruction of an object from multiple Xray images, we aim at a classification of sets with certain ... 
How to choose a winner: the mathematics of social choice
[SNAP2015009EN] (Mathematisches Forschungsinstitut Oberwolfach, 2015)Suppose a group of individuals wish to choose among several options, for example electing one of several candidates to a political office or choosing the best contestant in a skating competition. The group might ask: what ... 
Invitation to quiver representation and Catalan combinatorics
[SNAP2021004EN] (Mathematisches Forschungsinstitut Oberwolfach, 20210408)Representation theory is an area of mathematics that deals with abstract algebraic structures and has numerous applications across disciplines. In this snapshot, we will talk about the representation theory of a class ... 
Limits of graph sequences
[SNAP2019010EN] (Mathematisches Forschungsinstitut Oberwolfach, 20190904)Graphs are simple mathematical structures used to model a wide variety of reallife objects. With the rise of computers, the size of the graphs used for these models has grown enormously. The need to efficiently represent ... 
On Logic, Choices and Games
[SNAP2019009EN] (Mathematisches Forschungsinstitut Oberwolfach, 20190904)Can we always mathematically formalise our taste and preferences? We discuss how this has been done historically in the field of game theory, and how recent ideas from logic and computer science have brought an interesting ... 
Das Problem der Kugelpackung
[SNAP2016004DE] (Mathematisches Forschungsinstitut Oberwolfach, 2016)Wie würdest du Tennisbälle oder Orangen stapeln? Oder allgemeiner formuliert: Wie dicht lassen sich identische 3dimensionale Objekte überschneidungsfrei anordnen? Das Problem, welches auch Anwendungen in der digitalen ... 
Random sampling of domino and lozenge tilings
[SNAP2016002EN] (Mathematisches Forschungsinstitut Oberwolfach, 2016)A grid region is (roughly speaking) a collection of “elementary cells” (squares, for example, or triangles) in the plane. One can “tile” these grid regions by arranging the cells in pairs. In this snapshot we review different ... 
The Robinson–Schensted algorithm
[SNAP2022002EN] (Mathematisches Forschungsinstitut Oberwolfach, 20220506)I am going to describe the Robinson–Schensted algorithm which transforms a permutation of the numbers from 1 to n into a pair of combinatorial objects called “standard Young tableaux”. I will then say a little bit about a ... 
Snake graphs, perfect matchings and continued fractions
[SNAP2019001EN] (Mathematisches Forschungsinstitut Oberwolfach, 20190213)A continued fraction is a way of representing a real number by a sequence of integers. We present a new way to think about these continued fractions using snake graphs, which are sequences of squares in the plane. You ... 
Tropical geometry
[SNAP2018007EN] (Mathematisches Forschungsinstitut Oberwolfach, 20180719)What kind of strange spaces hide behind the enigmatic name of tropical geometry? In the tropics, just as in other geometries, one of the simplest objects is a line. Therefore, we begin our exploration by considering tropical ... 
Ultrafilter methods in combinatorics
[SNAP2021006EN] (Mathematisches Forschungsinstitut Oberwolfach, 20210625)Given a set X, ultrafilters determine which subsets of X should be considered as large. We illustrate the use of ultrafilter methods in combinatorics by discussing two cornerstone results in Ramsey theory, namely ...