Current theories of massless free particle assume unitary space inversion and anti-unitary time reversal operators. In so doing robust classes possible are discarded. the present work systems derived through a strictly deductive development from principle relativistic invariance, that kind or operator is ruled out only if it causes inconsistencies. As results, new consistent for isolated explic...

When there is uncertainty about interest rates (typically due to either illiquidity or defaultability of zero coupon bonds) the cash-additivity assumption on risk measures becomes problematic. When this assumption is weakened, to cash-subadditivity for example, the equivalence between convexity and the diversi…cation principle no longer holds. In fact, this principle only implies (and it is imp...