Publications (22)
On metric Ramsey-type phenomena
Yair Bartal, Nathan Linial, Manor Mendel +1
The main question studied in this article may be viewed as a nonlinear analogue of Dvoretzky's theorem in Banach space theory or as part of Ramsey theory in combinatorics. Given a…
Limitations to Frechet's Metric Embedding Method
Yair Batal, Nathan Linial, Manor Mendel +1
Frechet's classical isometric embedding argument has evolved to become a major tool in the study of metric spaces. An important example of a Frechet embedding is Bourgain's embeddi…
Asymptotically Almost Every -regular Graph has an Internal Partition
Nathan Linial, Sria Louis
An internal partition of a graph is a partitioning of the vertex set into two parts such that for every vertex, at least half of its neighbors are on its side. We prove that for ev…
An upper bound on the number of high-dimensional permutations
Nathan Linial, Zur Luria
What is the higher-dimensional analog of a permutation? If we think of a permutation as given by a permutation matrix, then the following definition suggests itself: A d-dimensiona…
Are stable instances easy?
Yonatan Bilu, Nathan Linial
We introduce the notion of a stable instance for a discrete optimization problem, and argue that in many practical situations only sufficiently stable instances are of interest. Th…
Chernoff's Inequality - A very elementary proof
Nathan Linial, Zur Luria
We give a very simple proof of a strengthened version of Chernoff's Inequality. We derive the same conclusion from much weaker assumptions.
Monotone Subsequences in High-Dimensional Permutations
Nathan Linial, Michael Simkin
This paper is part of the ongoing effort to study high-dimensional permutations. We prove the analogue to the ErdÅs-Szekeres theorem: For every , every order- -dimens…
An Upper bound on the number of Steiner triple systems
Nathan Linial, Zur Luria
Let STS(n) denote the number of Steiner triple systems on n vertices, and let F(n) denote the number of 1-factorizations of the complete graph on n vertices. We prove the following…
Sum complexes - a new family of hypertrees
Nathan Linial, Roy Meshulam, Mishael Rosenthal
A k-dimensional hypertree X is a k-dimensional complex on n vertices with a full (k-1)-dimensional skeleton and \binom{n-1}{k} facets such that H_k(X;Q)=0. Here we introduce the fo…
Finite metric spaces--combinatorics, geometry and algorithms
Nathan Linial
Finite metric spaces arise in many different contexts. Enormous bodies of data, scientific, commercial and others can often be viewed as large metric spaces. It turns out that the…
On regular hypergraphs of high girth
David Ellis, Nathan Linial
We give lower bounds on the maximum possible girth of an -uniform, -regular hypergraph with at most vertices, using the definition of a hypergraph cycle due to Berge. The…
How neighborly can a centrally symmetric polytope be?
Nathan Linial, Isabella Novik
We show that there exist k-neighborly centrally symmetric d-dimensional polytopes with 2(n+d) vertices, where k(d,n)=Theta(d/(1+log ((d+n)/d))). We also show that this bound is tig…
Discrepancy of High-Dimensional Permutations
Nathan Linial, Zur Luria
Let be an order- Latin square. For , let be the number of triples such that . We conjectur…
Constructing expander graphs by 2-lifts and discrepancy vs. spectral gap
Yonatan Bilu, Nathan Linial
We present a new explicit construction for expander graphs with nearly optimal spectral gap. The construction is based on a series of 2-lift operations. Let be a graph on v…
On the Lipschitz Constant of the RSK Correspondence
Nayantara Bhatnagar, Nathan Linial
We view the RSK correspondence as associating to each permutation a Young diagram , i.e. a partition of . Suppose now that is left-multiplied by …
Tight products and Expansion
Amit Daniely, Nathan Linial
In this paper we study a new product of graphs called {\em tight product}. A graph is said to be a tight product of two (undirected multi) graphs and , if $V(H)=V(G_…
A counterexample to a conjecture of Björner and Lovász on the -coloring complex
Shlomo Hoory, Nathan Linial
Associated with every graph of chromatic number is another graph . The vertex set of consists of all -colorings of , and two -colorings are adjacent wh…
The expected genus of a random chord diagram
Nathan Linial, Tahl Nowik
To any generic curve in an oriented surface there corresponds an oriented chord diagram, and any oriented chord diagram may be realized by a curve in some oriented surface. The gen…
On the vertices of the d-dimensional Birkhoff polytope
Nathan Linial, Zur Luria
Consider the Birkhoff polytope of n by n doubly-stochastic matrices. As the Birkhoff-von Neumann theorem famously states, its vertex set coincides with the set of all n by n permut…
On Metric Ramsey-type Dichotomies
Yair Bartal, Nathan Linial, Manor Mendel +1
The classical Ramsey theorem, states that every graph contains either a large clique or a large independent set. Here we investigate similar dichotomic phenomena in the context of…
On the phase transition in random simplicial complexes
Nathan Linial, Yuval Peled
It is well-known that the model of random graphs undergoes a dramatic change around . It is here that the random graph is, almost surely, no longer a forest, a…
Eigenvectors of random graphs: Nodal domains
Yael Dekel, James R. Lee, Nathan Linial
We initiate a systematic study of eigenvectors of random graphs. Whereas much is known about eigenvalues of graphs and how they reflect properties of the underlying graph, relative…