Invariant manifolds near $$L_1$$ and $$L_2$$ in the quasi-bicircular problem

G-invariant norms and bicircular projections

It is shown that for many finite dimensional normed vector spaces V over C, a linear projection P : V → V will have nice structure if P + λ(I − P ) is an isometry for some complex unit not equal to one. From these results, one can readily determine the structure of bicircular projections, i.e., those linear projections P such that P + μ(I − P ) is a an isometry for every complex unit μ. The key...

Invariant manifolds near hyperbolic fixed points

In these notes we discuss obstructions to the existence of local invariant manifolds in some smoothness class, near hyperbolic fixed points of diffeomorphisms. We present an elementary construction for continuously differentiable invariant manifolds, that are not necessarily normally hyperbolic, near attracting fixed points. The analogous theory for invariant manifolds near hyperbolic equilbria...

Balanced realizations near stable invariant manifolds

It is shown that the notion of balancing a state space realization about a stable, isolated equilibrium point can be generalized to systems possessing only a stable invariant regular submanifold of arbitrary dimension, for example, a stable limit cycle.

Invariant Foliations near Normally Hyperbolic Invariant Manifolds for Semiflows

Let M be a compact C1 manifold which is invariant and normally hyperbolic with respect to a C1 semiflow in a Banach space. Then in an -neighborhood of M there exist local C1 center-stable and center-unstable manifolds W cs( ) and W cu( ), respectively. Here we show that W cs( ) and W cu( ) may each be decomposed into the disjoint union of C1 submanifolds (leaves) in such a way that the semiflow...

On the vertical families of two-dimensional tori near the triangular points of the Bicircular problem