arXiv subjects

L. Lovász

Publications and source records attributed to L. Lovász.

3 recordsLinked to original sources

arXiv2024

Logarithmic kinetics and bundling in physical networks

We explore the impact of volume exclusion on the local assembly of linear physical networks, where nodes and links are hard-core rigid objects. To do so, we introduce a minimal 3D model that helps us zoom into confined regions of these networks whose distant parts are sequentially connected by links with a very large aspect ratio. We show that the kinetics of link adhesion is logarithmic, as opposed to the algebraic growth in lower dimensions, and we attribute this qualitatively different behavior to a spontaneous delay of depletion forces caused by the 3D nature of the problem. Equally important, we find that this slow kinetics is metastable, allowing us to analytically predict an algebraic growth due to the formation of local bundles. Our findings offer a benchmark to study the local assembly of physical networks, with implications for non-equilibrium nest-like packings.

cond-mat.dis-nn↗

arXiv2009

Approximate Counting and Quantum Computation

Motivated by the result that an `approximate' evaluation of the Jones polynomial of a braid at a $5^{th}$ root of unity can be used to simulate the quantum part of any algorithm in the quantum complexity class BQP, and results relating BQP to the counting class GapP, we introduce a form of additive approximation which can be used to simulate a function in BQP. We show that all functions in the classes #P and GapP have such an approximation scheme under certain natural normalisations. However we are unable to determine whether the particular functions we are motivated by, such as the above evaluation of the Jones polynomial, can be approximated in this way. We close with some open problems motivated by this work.

cs.CC↗

arXiv2009

Limits of randomly grown graph sequences

Motivated in part by various sequences of graphs growing under random rules (like internet models), convergent sequences of dense graphs and their limits were introduced by Borgs, Chayes, Lovász, Sós and Vesztergombi and by Lovász and Szegedy. In this paper we use this framework to study one of the motivating class of examples, namely randomly growing graphs. We prove the (almost sure) convergence of several such randomly growing graph sequences, and determine their limit. The analysis is not always straightforward: in some cases the cut distance from a limit object can be directly estimated, in other case densities of subgraphs can be shown to converge.

math.CO↗