which scientist is known for the kolmogorov–arnold representation theorem and the arnold's rouble problem ?
select distinct var_uri where brack_open var_uri dbo_knownFor dbr_Kolmogorov–Arnold_representation_theorem sep_dot var_uri rdf_type dbo_Scientist sep_dot var_uri dbo_knownFor dbr_Arnold's_rouble_problem sep_dot brack_close