Minimal fq-martingale measures for exponential Lévy processes
Minimal fq-martingale measures for exponential Lévy processes
Let L be a multidimensional Lévy process under P in its own filtration. The fq-minimal martingale measure Qq is defined as that equivalent local martingale measure for $\mathcal {E}(L)$ which minimizes the fq-divergence E[(dQ/dP)q] for fixed q∈(−∞, 0)∪(1, ∞). We give necessary and sufficient conditions for the existence of Qq …