ARCHIV DER MATHEMATIK, cilt.111, ss.225-229, 2018 (SCI-Expanded)
We prove that a κ-existentially closed group of cardinality λ exists whenever κ ≤ λ are uncountable cardinals with λ^{<κ} = λ. In particular, we show that there exists a κ-existentially closed group of cardinality
κ for regular κ with 2^{<κ} = κ. Moreover, we prove that there exists no
κ-existentially closed group of cardinality κ for singular κ. Assuming the
generalized continuum hypothesis, we completely determine the cardinals
κ ≤ λ for which a κ-existentially closed group of cardinality λ exists