arXiv subjects

David Corlin Marchand

Publications and source records attributed to David Corlin Marchand.

3 recordsLinked to original sources

arXiv2024

Line-of-sight Cox percolation on Poisson-Delaunay triangulation

In this work, percolation properties of device-to-device (D2D) networks in urban environments are investigated. The street system is modeled by a Poisson-Delaunay triangulation (PDT). Users are of two types: given either by a Cox process supported by the edges of the PDT or by a Bernoulli process on the vertices of the PDT (i.e. on streets and at crossroads). Percolation of the resulting connectivity graph G p,$\lambda$,r is interpreted as long-range connection in the D2D network. According to the parameters p, $\lambda$, r of the model, we state several percolation regimes in Theorem 1 (see also Fig. 3). This work completes and specifies results of Le Gall et al [23]. To do it, we take advantage of a percolation tool, inspired by enhancement techniques, used to our knowledge for the first time in the context of communication networks.

math.PR↗

arXiv2023

Percolation on supercritical causal triangulations

We study oriented percolation on random causal triangulations, those are random planar graphs obtained roughly speaking by adding horizontal connections between vertices of an infinite tree. When the underlying tree is a geometric Galton--Watson tree with mean $m>1$, we prove that the oriented percolation undergoes a phase transition at $p_c(m)$, where $p_c(m) = \fracη{1+η}$ with $η= \frac{1}{m+1} \sum_{n \geq 0} \frac{m-1}{m^{n+1}-1}$. We establish that strictly above the threshold $p_c(m)$, infinitely many infinite components coexist in the map. This is a typical percolation result for graphs with a hyperbolic flavour. We also demonstrate that large critical oriented percolation clusters converge after rescaling towards the Brownian continuum random tree. The proof is based on a Markovian exploration method, similar in spirit to the peeling process of random planar maps.

math.PR↗

arXiv2018

Influence of the seed in affine preferential attachment trees

We study randomly growing trees governed by the affine preferential attachment rule. Starting with a seed tree $S$, vertices are attached one by one, each linked by an edge to a random vertex of the current tree, chosen with a probability proportional to an affine function of its degree. This yields a one-parameter family of preferential attachment trees $(T_n^S)_{n\geq|S|}$, of which the linear model is a particular case. Depending on the choice of the parameter, the power-laws governing the degrees in $T_n^S$ have different exponents. We study the problem of the asymptotic influence of the seed $S$ on the law of $T_n^S$. We show that, for any two distinct seeds $S$ and $S'$, the laws of $T_n^S$ and $T_n^{S'}$ remain at uniformly positive total-variation distance as $n$ increases. This is a continuation of Curien et al. (2015), which in turn was inspired by a conjecture of Bubeck et al. (2015). The technique developed here is more robust than previous ones and is likely to help in the study of more general attachment mechanisms.

math.PR↗