Normal forms for orthogonal similarity classes of skew-symmetric matrices

Exponentials of skew-symmetric matrices and logarithms of orthogonal matrices

The authors show that there is a generalization of Rodrigues’ formula for computing the exponential map exp: so(n)→SO(n) from skewsymmetric matrices to orthogonal matrices when n ≥ 4, and give a method for computing some determination of the (multivalued) function log: SO(n) → so(n). The key idea is the decomposition of a skew-symmetric n×n matrix B in terms of (unique) skew-symmetric matrices ...

The Jordan Canonical Forms of complex orthogonal and skew-symmetric matrices: characterization and examples

Orthogonal Decomposition Defined by a Pair of Skew-Symmetric Forms

Proof. We use induction on n. For n = 1, the result is immediate, First, observe there exist linear transformations Ui (i = 1, 2): X + X such that (U,x, y) = &(x, y). For define&: X -R by Liz(y) = #Q(x, y). Then L,, is a linear functional and since X is an inner product space, there exists Z< E X with L,,(y) = (zi, y) by the canonical isomorphism between X and its dual. Define the transformatio...

Normal Forms for Skew-symmetric Matrices and Hamiltonian Systems with First Integrals Linear in Momenta

Using an appropriate notion of equivalence, those classical Hamiltonian systems which admit a first integral of motion polynomial of degree one in momentum are classified. The classification is effected by means of finding a normal form for a skew-symmetric matrix under the action of orthogonal symmetry.

Commutators of Skew-Symmetric Matrices

In this paper we develop a theory for analysing the size of a Lie bracket or commutator in a matrix Lie algebra. Complete details are given for the Lie algebra so(n) of skew symmetric matrices. 1 Norms and commutators in Mn[R] and so(n) This paper is concerned with the following question. Let g be a Lie algebra (Carter, Segal & Macdonald 1995, Humphreys 1978, Varadarajan 1984). Given X,Y ∈ g an...