Diffusions with rank-based characteristics and values in the nonnegative quadrant

作者：Ichiba Tomoyuki^*; Karatzas Ioannis; Prokaj Vilmos

来源：Bernoulli, 2013, 19(5B): 2455-2493.

DOI：10.3150/12-BEJ459

• diffusion with reflection and rank-dependent characteristics
• semimartingale local time
• skew representations
• Skorokhod problem
• sum-of-exponential stationary densities
• Tanaka formula and equation
• unfolding nonnegative semimartingales
• weak and strong solutions

We construct diffusions with values in the nonnegative orthant, normal reflection along each of the axes, and two pairs of local drift/variance characteristics assigned according to rank; one of the variances is allowed to vanish, but not both. The construction involves solving a system of coupled Skorokhod reflection equations, then "unfolding" the Skorokhod reflection of a suitable semimartingale in the manner of Prokaj (Statist. Probab. Lett. 79 (2009) 534-536). Questions of pathwise uniqueness and strength are also addressed, for systems of stochastic differential equations with reflection that realize these diffusions. When the variance of the laggard is at least as large as that of the leader, it is shown that the corner of the quadrant is never visited.

• 出版日期2013-11