TY - JOUR T1 - On the Space of Symmetric Operators with Multiple Ground States JF - Functional Analysis and its Applications, Volume 45, Issue 4, December 2011, Pages 241-251 Y1 - 2011 A1 - Andrei A. Agrachev KW - Multiple eigenvalue AB - We study homological structure of the filtrations of the spaces of self-adjoint operators by the multiplicity of the ground state. We consider only operators acting in a finite dimensional complex or real Hilbert space but infinite dimensional generalizations are easily guessed. PB - SISSA UR - http://hdl.handle.net/1963/7069 U1 - 6392 U2 - Mathematics U4 - 1 U5 - MAT/03 GEOMETRIA ER -