activity
20152020
most citedReal Polynomial Rings and Domain Invariance

3 citations · 7 across the 6 of their papers we have counts for

collaborators

6 papers

math.FA2020

Parity of n-Frames with Application to Non-Procrustean Orthogonalization

Jon A. Sjogren

The space of complete orthonormal frames in Euclidean space is not path connected. In fact it has exactly two path components, containing respectively the coordinate frame of n sta…

math.FA2018★ 1 cited

Complex Axis and de Medeiros' Campo Vetorial

Jon A. Sjogren

The Complex Axis theorem states that any endomorphism of a finite-dimensional complex vector space affords an eigen-vector (or "invariant axis"). A geometric proof of this geometri…

math.FA2017★ 2 cited

Homogeneous Systems and Euclidean Topology

Jon A. Sjogren

The Theorem on Invariance of Domain due to L.E.J. Brouwer states that one connected, compact (Hausdorff) m-dimensional manifold embedded into another actually realizes a homeomorph…

math.FA2015

Complex Odd-Dimensional Endomorphism and Topological Degree

Jon A. Sjogren

A linear mapping upon real n-dimensional space, where the dimension n is odd, has a real eigenvalue-eigenvector pair. The corresponding statement for complex vector spaces holds tr…

math.CV2015★ 1 cited

Polynomial Roots and Open Mappings

Jon A. Sjogren

The "openness" of a complex polynomial mapping is discussed and applied to the Fundamental Theorem of Algebra. In this category fall proofs of S. Wolfenstein, R.L. Thompson, J. Mil…

math.GT2015★ 3 cited

Real Polynomial Rings and Domain Invariance

Jon A. Sjogren

Recent proofs of classical theorems in polynomial algebra and functional analysis are discussed, which use tools from the topology of real manifolds. Simpler proofs were discovered…