Cone exponents of Brownian motions with particular drifts

Herein, we describe multidimensional Brownian motions for d = 2; 3 with drifts whose order is the same as that of the mean displacement of a Brownian motion. We consider the probabilities that the processes remain in specific cones for a considerable amount of time. We obtain exponents expressing the probabilities, which are different from that of the ordinary Brownian motion. Finally, we suggest an open problem concerning the exact values.