English

Atypical stars on a directed landscape geodesic

Probability 2024-04-03 v3

Abstract

In random geometry, a recurring theme is that any two geodesics emanating from a typical point part ways at a strictly positive distance from the above point, and we call such points as 11-stars. However, the measure zero set of atypical stars, the points where such coalescence fails, is typically uncountable and the corresponding Hausdorff dimensions of these sets have been heavily investigated for a variety of models including the directed landscape, Liouville quantum gravity and the Brownian map. In this paper, we consider the directed landscape -- the scaling limit of last passage percolation as constructed in the work Dauvergne-Ortmann-Vir\'ag '18 -- and look into the Hausdorff dimension of the set of atypical stars lying on a geodesic. We show that the above dimension is almost surely equal to 1/31/3. This is in contrast to Ganguly-Zhang '22, where it was shown that set of atypical stars on the line {x=0}\{x=0\} has dimension 2/32/3. This reduction of the dimension from 2/32/3 to 1/31/3 yields a quantitative manifestation of the smoothing of the environment around a geodesic with regard to exceptional behaviour.

Keywords

Cite

@article{arxiv.2211.05734,
  title  = {Atypical stars on a directed landscape geodesic},
  author = {Manan Bhatia},
  journal= {arXiv preprint arXiv:2211.05734},
  year   = {2024}
}

Comments

28 pages, 4 figures; minor edits

R2 v1 2026-06-28T05:37:15.344Z