Title: On the quasi-sure superhedging duality with frictions,
Abstract: We prove the superhedging duality for a discrete-time financial market with
proportional transaction costs under portfolio constraints and model
uncertainty. Frictions are modeled through solvency cones as in the original
model of [Kabanov, Y., Hedging and liquidation under transaction costs in
currency markets. Fin. Stoch., 3(2):237-248, 1999] adapted to the quasi-sure
setup of [Bouchard, B. and Nutz, M., Arbitrage and duality in nondominated
discrete-time models. Ann. Appl. Probab., 25(2):823-859, 2015]. Our results
hold under the condition of No Strict Arbitrage and under the efficient
friction hypothesis.