Jacopo

What is… a permuton?

How does a large random permutation behave? We will try to answer this question for different classical models of random permutations, such as uniform permutations, pattern-avoiding permutations, Mallows permutations and many others. An appropriate framework to describe the asymptotic behaviour of these pemutations is to use a quite recent notion of scaling limits for permutations, …

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Enumerative Combinatorics | 2018

This is the webpage for the course of Enumerative Combinatorics. Teacher: Mathilde Bouvel Lectures: Th 15.00 – 17.00, Room: Y27H28 Exercises: Th 8.00 – 9.45, Room: Y27H46 UZH-Webpage of the course I’m in charge of the exercise sessions for this course. I will publish here one exercise sheet per week. Exercises 1 (Solutions 1) Exercises …

Enumerative Combinatorics | 2018Read More »

[1] Local convergence for permutations and local limits for uniform ρ-avoiding permutations with |ρ|=3. Probability Theory and Related Fields 176 (2020), no. 1-2, pp. 449–531.

We set up a new notion of local convergence for permutations and we prove a characterization in terms of proportions of consecutive pattern occurrences. We also characterize random limiting objects for this new topology introducing a notion of “shift-invariant” property (corresponding to the notion of unimodularity for random graphs). We then study two models in …

[1] Local convergence for permutations and local limits for uniform ρ-avoiding permutations with |ρ|=3. Probability Theory and Related Fields 176 (2020), no. 1-2, pp. 449–531.Read More »

Local convergence for random permutations: the case of uniform pattern-avoiding permutations.

For large combinatorial structures, two main notions of convergence can be defined: scaling limits and local limits. In particular for graphs, both notions are well-studied and well-understood. For permutations only a notion of scaling limits, called permutons, has been recently introduced. The convergence for permutons has also been characterized by frequencies of pattern occurrences. We …

Local convergence for random permutations: the case of uniform pattern-avoiding permutations.Read More »