@phdthesis{Gerhold2015,
  author    = {Malte Gerhold},
  title     = {On Several Problems in the Theory of Comonoidal Systems and Subproduct Systems},
  journal    = {{\"U}ber einige Fragestellungen in der Theorie der komonoidalen Systeme und Subproduktsysteme},
  url       = {https://nbn-resolving.org/urn:nbn:de:gbv:9-002244-6},
  year      = {2015},
  abstract  = {The constructions of L{\´e}vy processes from convolution semigroups and of product systems from subproduct systems respectively, are formally quite similar. Since there are many more comparable situations in quantum stochastics, we formulate a general categorial concept (comonoidal systems), construct corresponding inductive systems and show under suitable assumptions general properties of the corresponding inductive limits. Comonoidal systems in different tensor categories play a role in all chapters of the thesis. Additive deformations are certain comonoidal systems of algebras. These are obtained by deformation of the algebra structure of a bialgebra. If the bialgebra is even a Hopf algebra, then compatibility with the antipode automatically follows. This remains true also in the case of braided Hopf algebras. Subproduct systems are comonoidal systems of Hilbert spaces. In the thesis we deal with the question, what are the possible dimensions of finite-dimensional subproduct systems. In discrete time, this can be reduced to the combinatorial problem of determining the complexities of factorial languages. We also discuss the rational and continuous time case. A further source for comonoidal systems are universal products, which are used in quantum probability to model independence. For the (r,s)-products, which were recently introduced by S. Lachs, we determine the corresponding product of representations by use of a generalized GNS-construction.},
  language  = {en}
}