Susceptible-infected-susceptible epidemics on the complete graph and the star graph: Exact analysis

Since mean-field approximations for susceptible-infected-susceptible (SIS) epidemics do not always predict the correct scaling of the epidemic threshold of the SIS metastable regime, we propose two novel approaches: (a) an ?-SIS generalized model and (b) a modified SIS model that prevents the epidemic from dying out (i.e., without the...

Asymptotics: Particles, Processes and Inverse Problems. Festschrift for Piet Groeneboom

Second class particles and cube root asymptotics for Hammersley’s process

We show that, for a stationary version of Hammersley’s process, with Poisson sources on the positive x-axis and Poisson sinks on the positive y-axis, the variance of the length of a longest weakly North–East path L(t, t) from (0, 0) to (t, t) is equal to 2E(t ? X(t))+, where X(t) is the location of a second class particle at time t . This...

Hammersley's process with sources and inks

We show that, for a stationary version of Hammersley’s process, with Poisson “sources” on the positive x-axis, and Poisson “sinks” on the positive y-axis, an isolated second-class particle, located at the origin at time zero, moves asymptotically, with probability 1, along the characteristic of a conservation equation for Hammersley’s process....

On the testability of the CAR assumption

In recent years a popular nonparametric model for coarsened data is an assumption on the coarsening mechanism called coarsening at random (CAR). It has been conjectured in several papers that this assumption cannot be tested by the data, that is, the assumption does not restrict the possible distributions of the data. In this paper we will show...