9 6 8 ▁he ▁was ▁given ▁a ▁full ▁professor ship ▁in ▁theoretical ▁physics , ▁ret iring ▁in ▁ 1 9 9 8 . ▁ ▁He ▁is ▁married ▁with ▁three ▁children . ▁ ▁Research ▁He ▁is ▁considered ▁one ▁of ▁the ▁found ers ▁of ▁non linear ▁dynamics ▁and ▁cha os ▁theory . ▁His ▁work ▁on ▁tur bul ence ▁contributed ▁to ▁an ▁understanding ▁of ▁the ▁transition ▁from ▁l amin ar ▁to ▁tur bul ent ▁flow . ▁He ▁provided ▁contributions ▁to ▁the ▁description ▁of ▁a ▁las er ▁using ▁non linear ▁dynamics . ▁With ▁Stefan ▁Thom ae ▁he ▁produced ▁a ▁value ▁for ▁the ▁Fe igen baum ▁constant . ▁ ▁He ▁is ▁also ▁one ▁of ▁the ▁leading ▁theoret icians ▁in ▁the ▁fields ▁of ▁fluid ▁dynamics ▁and ▁theory ▁of ▁tur bul ence , ▁st ochastic ▁processes , ▁phase ▁trans itions , ▁las er ▁physics , ▁nuclear ▁physics , ▁transport ▁theory , ▁B ose - E ▁inst ein ▁cond ens ation ▁and ▁the ▁general ▁statistical ▁physics , ▁as ▁well ▁as ▁mathematical ▁physics ▁and ▁functional ▁analysis . ▁ ▁Hon ours ▁and ▁awards ▁In ▁ 1 9 9 1 ▁he ▁was ▁elected ▁a ▁member ▁of ▁the ▁European ▁Academy ▁of ▁Sciences ▁and ▁Arts . ▁In ▁ 1 9 9 5 ▁he ▁was ▁awarded ▁the ▁pr estig ious ▁Max ▁Plan ck ▁Medal ▁for ▁out standing ▁achiev ements ▁in ▁the ▁field ▁of ▁theoretical ▁physics . ▁In ▁ 2 0 0 6 ▁he ▁received ▁a ▁doctor ate ▁from ▁the ▁University ▁of ▁D uis burg - E ss en ▁for ▁his ▁work ▁on ▁the ▁theory ▁of ▁tur bul