Convolution semigroups of probability measures with parameter in a cone in a Euclidean space generalize usual convolution semigroups with parameter in $[0,\infty)$. A characterization of such semigroups is given and examples are studied. Subordination of cone-parameter convolution semigroups by cone-valued cone-parameter convolution semigroups is introduced. Its general description is given and inheritance properties are shown. In the study the distinction between cones with and without strong bases is important.
"Cone-Parameter Convolution Semigroups and Their Subordination." Tokyo J. Math. 26 (2) 503 - 525, December 2003. https://doi.org/10.3836/tjm/1244208605