This is the first book on the topic of study of modules invariant under automorphisms of their envelopes and covers. Containing plentiful examples and open problems, it is a valuable resource for graduate students and researchers in algebra who wish to learn the state of the art in this area of module theory.

Ashish K. Srivastava is Professor of Mathematics at Saint Louis University. He has published more than 40 research papers and co-authored the monograph Cyclic Modules and the Structure of Rings (2012).

1. Preliminaries; 2. Modules invariant under automorphisms of envelopes; 3. Structure and properties of modules invariant under automorphisms; 4. Automorphism-invariant modules; 5. Modules coinvariant under automorphisms of their covers; 6. Schröder-Bernstein problem; 7. Automorphism-extendable modules; 8. Automorphism-liftable modules; 9. Open problems; References; Index.