▁Del itz sch ▁E ld rit ch ▁( disambiguation ) ▁E lic ▁( disambiguation ) ▁El it ▁( disambiguation ) <0x0A> </s> ▁In ▁physics , ▁the ▁Call an – Sym anz ik ▁equation ▁is ▁a ▁differential ▁equation ▁describing ▁the ▁evolution ▁of ▁the ▁n - point ▁correlation ▁functions ▁under ▁variation ▁of ▁the ▁energy ▁scale ▁at ▁which ▁the ▁theory ▁is ▁defined ▁and ▁involves ▁the ▁beta ▁function ▁of ▁the ▁theory ▁and ▁the ▁anom alous ▁dimensions . ▁ ▁As ▁an ▁example , ▁for ▁a ▁quantum ▁field ▁theory ▁with ▁one ▁mass less ▁scalar ▁field ▁and ▁one ▁self - cou pling ▁term , ▁denote ▁the ▁bare ▁field ▁strength ▁by ▁ ▁and ▁the ▁bare ▁coupling ▁constant ▁by ▁. ▁In ▁the ▁process ▁of ▁ren ormal isation , ▁a ▁mass ▁scale ▁M ▁must ▁be ▁chosen . ▁Depending ▁on ▁M , ▁the ▁field ▁strength ▁is ▁res c aled ▁by ▁a ▁constant : ▁, ▁and ▁as ▁a ▁result ▁the ▁bare ▁coupling ▁constant ▁ ▁is ▁corresponding ly ▁shift ed ▁to ▁the ▁ren ormal ised ▁coupling ▁constant ▁g . ▁ ▁Of ▁physical ▁importance ▁are ▁the ▁ren ormal ised ▁n - point ▁functions , ▁computed ▁from ▁connected ▁Fe yn man ▁diag rams , ▁sch emat ically ▁of ▁the ▁form ▁ ▁For ▁a ▁given ▁choice ▁of ▁ren ormal isation ▁scheme , ▁the ▁computation ▁of ▁this ▁quantity ▁depends ▁on ▁the ▁choice ▁of ▁M , ▁which ▁affect s ▁the ▁shift ▁in ▁g ▁and ▁the ▁res cal ing ▁of ▁. ▁If ▁the ▁choice ▁of ▁ ▁is ▁slightly ▁alter ed ▁by ▁, ▁then ▁the ▁following ▁sh ifts ▁will ▁occur : ▁ ▁The