The contact process on random hyperbolic graphs: metastability and critical exponents

International audience; We consider the contact process on the model of hyperbolic random graph, in the regime when the degree distribution obeys a power law with exponent χ ∈ (1, 2) (so that the degree distribution has finite mean and infinite second moment). We show that the probability of non-extinction as the rate of infection goes to zero decays as a power law with an exponent that only depends on χ and which is the same as in the configuration model, suggesting some universality of this critical exponent. We also consider finite versions of the hyperbolic graph and prove metastability results, as the size of the graph goes to infinity.