▁professor ▁at ▁Cal tech ▁in ▁ 1 9 6 7 ▁and ▁the ▁Institute ▁for ▁Advanced ▁Study ▁in ▁ 1 9 6 9 . ▁In ▁ 1 9 8 6 , ▁he ▁became ▁a ▁professor ▁at ▁the ▁University ▁of ▁California , ▁San ▁Diego ▁( UC SD ) ▁in ▁ 1 9 8 8 ▁was ▁Head ▁of ▁Fac ulty . ▁He ▁played ▁a ▁leading ▁role ▁in ▁the ▁establishment ▁of ▁a ▁super comput er ▁center ▁at ▁U C SD ▁and ▁in ▁the ▁establishment ▁of ▁the ▁Institute ▁for ▁The oret ical ▁Physics ▁of ▁the ▁National ▁Science ▁Foundation ▁at ▁the ▁University ▁of ▁California , ▁Santa ▁Barbara . ▁ ▁In ▁the ▁ 1 9 6 0 s ▁he ▁worked ▁partly ▁in ▁collaboration ▁with ▁Murray ▁G ell - M ann ▁with ▁current ▁al gebras ▁of ▁particle ▁physics ▁and ▁models ▁with ▁ch iral ▁symmetry . ▁In ▁ 1 9 6 4 , ▁he ▁worked ▁on ▁S - matrix ▁methods ▁to ▁calculate ▁elect romagnet ic ▁corre ctions ▁to ▁strong ▁interactions , ▁including ▁the ▁mass ▁difference ▁between ▁pro tons ▁and ▁neut rons ▁with ▁Steven ▁Fra utsch i . ▁In ▁the ▁ 1 9 7 0 s , ▁he ▁studied ▁with ▁B ros l ▁Hass la cher ▁and ▁André ▁Ne ve u ▁quantum ▁field ▁theoretical ▁model ▁theories ▁( such ▁as ▁the ▁S ine - G ordon ▁model ▁and ▁the ▁G ross - Ne ve u ▁model ) ▁for ▁extended ▁particles ▁and ▁sem ic lass ical ▁approxim ations ▁([ W KB ▁approximation ] ▁[ ]) ▁for ▁their ▁analysis . ▁They ▁developed ▁the ▁D ash en