8 4 ▁to ▁ 1 9 8 7 ▁when ▁he ▁became ▁Senior ▁Phys ic ist . ▁He ▁has ▁held ▁Vis iting ▁Professor ships ▁and ▁Fellow ships ▁at ▁the ▁University ▁of ▁Texas , ▁Austin ; ▁the ▁University ▁of ▁California , ▁Santa ▁Barbara , ▁the ▁University ▁of ▁Ky oto ▁and ▁the ▁Isaac ▁Newton ▁Institute , ▁University ▁of ▁Cambridge . ▁He ▁took ▁up ▁his ▁professor ship ▁at ▁Texas ▁A & M ▁University ▁in ▁ 1 9 8 8 ▁and ▁was ▁appointed ▁Dist ingu ished ▁Professor ▁in ▁ 1 9 9 2 . ▁In ▁▁ 1 9 9 9 ▁he ▁moved ▁to ▁the ▁University ▁of ▁Michigan , ▁where ▁he ▁was ▁O sk ar ▁Klein ▁Professor ▁of ▁Physics . ▁In ▁ 2 0 0 1 , ▁he ▁was ▁elected ▁first ▁Director ▁of ▁the ▁Michigan ▁Center ▁for ▁The oret ical ▁Physics ▁and ▁was ▁re - elect ed ▁in ▁ 2 0 0 4 . ▁He ▁returned ▁again ▁to ▁Imperial ▁College , ▁London ▁and ▁became ▁Professor ▁of ▁Physics ▁and ▁Princi pal ▁of ▁the ▁Fac ulty ▁of ▁Phys ical ▁Sciences ▁in ▁ 2 0 0 5 . ▁ ▁He ▁was ▁appointed ▁Abd us ▁Sal am ▁Professor ▁of ▁The oret ical ▁Physics ▁in ▁ 2 0 0 6 . ▁He ▁won ▁the ▁Di rac ▁Medal ▁of ▁the ▁I OP ▁in ▁ 2 0 1 7 . ▁ ▁Cont ribution s ▁His ▁interests ▁lie ▁in ▁un ified ▁theories ▁of ▁the ▁elementary ▁particles , ▁quantum ▁gravity , ▁super gravity , ▁Kal u za – K lein ▁theory , ▁super strings , ▁super m emb