Guasoni, Paolo; Rásonyi, Miklós - In: Finance and Stochastics 19 (2015) 2, pp. 215-231
<Para ID="Par1">For any positive diffusion with minimal regularity, there exists a semimartingale with uniformly close paths that is a martingale under an equivalent probability. As a result, in models of asset prices based on such diffusions, arbitrage and bubbles alike disappear under proportional transaction...</para>