Noname manuscript No. (will be inserted by the editor) On the separable quotient problem J. C. Ferrando · J. K¸ akol · M. L´opez-Pellicer · W. ´ Sliwa Received: date / Accepted: date Abstract While the classic separable quotient problem remains open, we par- tially survey (and provide some new) general results related to this problem, and examine the existence of a particular infinite-dimensional separable quo- tient in some Banach spaces of vector-valued functions, linear operators and vector measures. Some of the results presented are consequence of well-known facts, several of them relative to the presence of complemented copies of the classic sequence spaces c 0 and ‘ p , for 1 ≤ p ≤∞. Keywords Banach space · barrelled space · separable quotient · vector- valued function space · linear operator space · vector measure space · tensor product · Radon-Nikod´ ym property Mathematics Subject Classification (2000) 46B28 · 46E27 · 46E30 The first three named authors were supported by Grant PROMETEO/2013/058 of the Conselleria d’Educaci´o, Investigaci´ o, Cultura i Esport of Generalitat Valenciana. The second named author was also supported by GA ˇ CR Project 16-34860L and RVO: 67985840. J. C. Ferrando Centro de Investigaci´on Operativa, Edificio Torretamarit, Avda de la Universidad Miguel Hern´andez, E-03202 Elche (Alicante). Spain E-mail: jc.ferrando@umh.es J. K¸ akol Faculty of Mathematics and Informatics. A. Mickiewicz University, 61-614 Pozna´ n, Poland E-mail: kakol@amu.edu.pl M. L´opez-Pellicer Depto. de Matem´atica Aplicada and IMPA. Universitat Polit`ecnica de Val`encia, E-46022 Valencia, Spain E-mail: mlopezpe@mat.upv.es W. ´ Sliwa Faculty of Mathematics and Natural Sciences University of Rzesz´ow, 35-310 Rzesz´ow, Poland E-mail: sliwa@amu.edu.pl