DISJOINT AMALGAMATION IN LOCALLY FINITE AEC
DISJOINT AMALGAMATION IN LOCALLY FINITE AEC
复制标题
局部有限 AEC 中的不相交合并
DOI:
--
复制
发表时间:
2017
期刊:
影响因子:
--
通讯作者:
M. Laskowski
中科院分区:
文献类型:
--
作者:
J. Baldwin;Martin Koerwien;M. Laskowski
Abstract We introduce the concept of a locally finite abstract elementary class and develop the theory of disjoint $left( { le lambda ,k}
ight)$ -amalgamation) for such classes. From this we find a family of complete ${L_{{omega _1},omega }}$ sentences ${phi _r}$ that a) homogeneously characterizes ${aleph _r}$ (improving results of Hjorth [11] and Laskowski–Shelah [13] and answering a question of [21]), while b) the ${phi _r}$ provide the first examples of a class of models of a complete sentence in ${L_{{omega _1},omega }}$ where the spectrum of cardinals in which amalgamation holds is other that none or all.