Descripción
**Hora de inicio:** 13:00. **Hora de fin:** 14:00.
We present some recent results on locally free modules. Notably, we explain a
new method of constructing locally free modules L(T,N) from two sorts of input
data: (1) T, the trees of finite sequences of ordinals < , and (2) countably pre-
sented Bass modules N. The construction is general enough to show, for example,
that the class of all flat Mittag-Leffler modules over any countable non-perfect ring
is not precovering.
References
[1] S. Bazzoni, J. ˇSˇtov´ıˇcek, Flat Mittag–Leffler modules over countable rings, Proc. Amer.
Math. Soc. 140 (2012), 1527-1533.
[2] G. Braun, J. Trlifaj, Strong submodules of almost projective modules, Pacific J. Math.
254 (2011), 73-87.
[3] R. G¨obel, J. Trlifaj, Approximations and Endomorphism Algebras of Modules, 2nd revised
and expanded ed., Vol. 1 - Approximations, GEM 41, W. de Gruyter, Berlin 2012.
[4] D.Herbera, J.Trlifaj, Almost free modules and Mittag-Leffler conditions, Advances in
Math. 229(2012), 3436-3467.
[5] J.ˇ Saroch, J.Trlifaj, Kaplansky classes, finite character, and @1-projectivity, to appear in
Forum Math. 24(2012).