arXiv subjects

Christopher J. Young

Publications and source records attributed to Christopher J. Young.

2 recordsLinked to original sources

arXiv2013

Subalgebra depths within the path algebra of an acyclic quiver

Constraints are given on the depth of diagonal subalgebras in generalized triangular matrix algebras. The depth of the top subalgebra B = A /rad A in a finite, connected, acyclic quiver algebra A over an algebraically closed field K is then computed. Also the depth of the primary arrow subalgebra 1K + rad A = B in A is obtained. The two types of subalgebras have depths 3 and 4 respectively, independent of the number of vertices. An upper bound on depth is obtained for the quotient of a subalgebra pair.

math.RT↗

arXiv2010

Exploring the Manifold of Seismic Waves: Application to the Estimation of Arrival-Times

We propose a new method to analyze seismic time series and estimate the arrival-times of seismic waves. Our approach combines two ingredients: the times series are first lifted into a high-dimensional space using time-delay embedding; the resulting phase space is then parametrized using a nonlinear method based on the eigenvectors of the graph Laplacian. We validate our approach using a dataset of seismic events that occurred in Idaho, Montana, Wyoming, and Utah, between 2005 and 2006. Our approach outperforms methods based on singular-spectrum analysis, waveleta nalysis, and STA/LTA.

physics.data-an↗