sum of stochastically continuous processes - MathOverflow most recent 30 from http://mathoverflow.net2013-05-22T15:29:37Zhttp://mathoverflow.net/feeds/question/115582http://www.creativecommons.org/licenses/by-nc/2.5/rdfhttp://mathoverflow.net/questions/115582/sum-of-stochastically-continuous-processessum of stochastically continuous processesPaolo 2012-12-06T07:00:27Z2012-12-06T08:29:42Z
<p>Hallo,
is the sum of two stochastically continuous processes again a stochastically continuous process? why?
Thank you very much,
Paolo.</p>
http://mathoverflow.net/questions/115582/sum-of-stochastically-continuous-processes/115588#115588Answer by Alexander Shamov for sum of stochastically continuous processesAlexander Shamov2012-12-06T08:29:42Z2012-12-06T08:29:42Z<p>Yes. A stochastically continuous process is a mapping $t \mapsto X_t \in L^0$ into the space of random variables that is continuous with $L^0$ given the topology of convergence in probability. Since $L^0$ is a topological vector space for this topology - in particular, addition is continuous - it is clear that $t \mapsto (X_t, Y_t) \mapsto X_t + Y_t$ is continuous as a composition of continuous mappings.</p>