July 15th, 2008, 11:01 am
suppose the cap market quotes(for say underlying=3m XYZ Libor) are that implied vols for tenors t1,t2,t3..tn and strikes k1,k2,k3,..km are givenand also each difference t2-t1=t3-t2=..~3mthen this would be demonstrable because cap can be broken into caplets as arbitrage free prices of individual caplet can be arrived at by addition subtraction of cap price equations. if one needs to interpolate then prices would become model dependent.