- H ass la cher - Ne ve u ▁method ▁( D H N ) ▁for ▁quant ization ▁of ▁solit ons ▁using ▁path ▁integr als . ▁After ▁the ▁discovery ▁of ▁instant ons ▁in ▁the ▁quantum ▁( Q CD ) ▁by ▁Poly akov , ▁he ▁exam ined ▁it ▁with ▁David ▁G ross ▁and ▁Curt is ▁Call an . ▁In ▁the ▁ 1 9 8 0 s , ▁he ▁worked ▁with ▁lattice ▁gauge ▁theory ▁s ▁and ▁found ▁with ▁Ne uber ger ▁( reg ard less ▁of ▁Giorg io ▁Paris i ) ▁is ▁an ▁upper ▁bound ▁for ▁the ▁H ig gs ▁Bos on ▁- ▁mass . ▁ ▁D ash en ▁was ▁also ▁involved ▁in ▁sound ▁propag ation ▁in ▁the ▁ocean ▁( with ▁military ▁applications ▁in ▁mind ), ▁where ▁he ▁applied ▁quantum ▁field ▁theoretical ▁methods ▁( such ▁as ▁path ▁integr als ▁and ▁the ▁ren ormal ization ▁group ) ▁on ▁the ▁problem ▁of ▁random ▁scatter ing ▁of ▁sound ▁in ▁the ▁ocean . ▁He ▁worked ▁with ▁his ▁J A SON ▁colle agues ▁Kenneth ▁M . ▁Watson ▁and ▁Freder ik ▁Zach arias en . ▁D ash en ▁was ▁senior ▁scientific ▁advis er ▁to ▁the ▁US ▁Navy , ▁including ▁the ▁committee ▁on ▁the ▁safety ▁of ▁S SBN s , ▁the ▁ro cket - car ry ing ▁sub mar ines , ▁and ▁matters ▁rel ating ▁to ▁sub marine ▁war fare . ▁He ▁was ▁a ▁member ▁of ▁the ▁J A SON ▁Def ense ▁Ad vis ory ▁Group . ▁ ▁D ash en ▁was ▁a ▁member ▁of ▁the ▁National ▁Academy ▁of ▁Sciences ▁since ▁