Soma Villanyi: Every d(d+1)-connected graph is globally rigid in d dimensions.

Image may be NSFW.
Clik here to view.

Today, I want to tell you a little about the following paper that solves a conjecture of Laszlo Lovász and Yechiam Yemini from 1982 and an even stronger conjecture of Bob Connelly, Tibor Jordán, and Walter Whiteley from 2013:

Every Image may be NSFW.
Clik here to view.-connected graph is globally rigid in Image may be NSFW.
Clik here to view., by Soma Villányi

Here is the abstract (h/t to Nati Linial for telling me about the paper):

Using a probabilistic method, we prove that Image may be NSFW.
Clik here to view.-connected graphs are rigid in Image may be NSFW.
Clik here to view., a conjecture of Lovász and Yemini. Then, using recent results on weakly globally linked pairs, we modify our argument to prove that Image may be NSFW.
Clik here to view.-connected graphs are globally rigid, too, a conjecture of Connelly, Jordán and Whiteley. The constant Image may be NSFW.
Clik here to view. is best possible. 

Let Image may be NSFW.
Clik here to view. be an abstract graph with Image may be NSFW.
Clik here to view. vertices. A Image may be NSFW.
Clik here to view.-dimensional framework is an embedding of the vertices of Image may be NSFW.
Clik here to view. into Image may be NSFW.
Clik here to view..  The embedding is flexible if there is a non-trivial flex, i.e., a non-trivial perturbation of the embedded vertices that keeps all the edge lengths fixed. Here, a trivial flex means a flex that comes from a rigid motion of the entire space. In other words, a trivial flex keeps the distances between every pair of embedded vertices fixed. An embedding is rigid if it is not flexible. There is a related linear notion of infinitesimal flex – an assignment of velocity vectors to the vertices so that the edge length is constant to the first degree. An embedding is globally rigid if every other embedding with the same distances between adjacent vertices is obtained by a rigid motion of Image may be NSFW.
Clik here to view..

A graph G is generically Image may be NSFW.
Clik here to view.-rigid or simply Image may be NSFW.
Clik here to view.-rigid if it is rigid for a generic embedding into Image may be NSFW.
Clik here to view.. (This is equivalent to being generically infinitesimally rigid.) A graph is globally Image may be NSFW.
Clik here to view.-rigid if it is globaly rigid for a generic embedding into Image may be NSFW.
Clik here to view..

Being Image may be NSFW.
Clik here to view.-rigid is a mysterious property of graphs and being globally Image may be NSFW.
Clik here to view.-rigid is an even more mysterious property. The edges of minimal Image may be NSFW.
Clik here to view.-rigid subgraphs of the complete graph on Image may be NSFW.
Clik here to view. vertices are the basis of the Image may be NSFW.
Clik here to view.-rigidity matroid. A graph is 1-rigid iff it is connected so we can think about Image may be NSFW.
Clik here to view.-rigidity as a strong form of connectedness. Another extension of graph connectivity is the notion of Image may be NSFW.
Clik here to view.-connected graph, namely a graph that remains connected when we delete every set of at most Image may be NSFW.
Clik here to view. vertices. Lovasz and Yemini proved in 1982 that every 6-connected graph is 2-rigid, and made the conjecture that Villanyi has just proved. Jackson and Jordán proved in 2005 that 6-connected graphs are globally 2-rigid.

Congratulations, Soma Villanyi, and happy and better new year to all