You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
A Characterization of Inner Automorphisms
Paul E. Schupp
Proceedings of the American Mathematical Society
Vol. 101, No. 2 (Oct., 1987), pp. 226-228
Published by: American Mathematical Society
Stable URL: http://www.jstor.org/stable/2045986
Page Count: 3
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
It turns out that one can characterize inner automorphisms without mentioning either conjugation or specific elements. We prove the following THEOREM Let G be a group and let α be an automorphism of G. The automorphism α is an inner automorphism of G if and only if α has the property that whenever G is embedded in a group H, then α extends to some automorphism of H.
Proceedings of the American Mathematical Society © 1987 American Mathematical Society