Let M(X) be a family of all equivalent local martingale measures for some locally bounded d-dimensional process X, and V be a positive process. Main result of the paper (Theorem 2.1) states that the process V is a supermartingale whatever Q in M(X), if and only if this process admits the...

We extend the duality approach developed by Kramkov and Schachermayer (1999) to cover the case of a general financial framework that includes models with some “imperfection”, such as constrained proportion portfolios, labor income, random endowment and large investor. General objective...

We extend the duality approach developed by Kramkov and Schachermayer (1999) to cover the case of a general financial framework that includes models with some “imperfection”, such as constrained proportion portfolios, labor income, random endowment and large investor. General objective...

A large financial market is described by a sequence of standard general models of continuous trading. It turns out that the absence of asymptotic arbitrage of the first kind is equivalent to the contiguity of sequence of objective probabilities with respect to the sequence of upper envelopes of...