Exact tricritical exponents for polymers at theFTHETApoint in two dimensions

We propose the exact values of the tricritical exponents of a collapsing polymer in two dimensions: ν=(4/7, γ=(8/7, and φ=(3/7. They are obtained in a model of self-avoiding walk on a hexagonal lattice, with random forbidden hexagons, whose percolation threshold gives the exact tricritical point. The infinitely many exact tricritical exponents then derived from Coulomb gas methods are critical exponents of the O(n=1) Ising model below ${\mathrm{T}}_{\mathrm{c}}$. The numerical check is very good.