7 citations · 10 across the 8 of their papers we have counts for
10 papers
Persistence in probability for stochastic delay equations with multiplicative noise
Mark van den Bosch, John Ioannis Stavroulakis
We study the stochastic delay equation \begin{equation*} dX(t)=[-γX(t)+r f(X(t-τ))]\,dt+σX(t)\,dW(t), \end{equation*} where , , and with eit…
Oscillation of Second-Order Delay Equations with Positive Feedback
John Ioannis Stavroulakis
We study oscillation of the second-order delay equation \[ x''(t)=x(τ(t)), \] with a nondecreasing delayed argument satisfying . Se…
A quantitative Schur comparison theorem for curves in CAT(k) spaces
Mohammad Ghomi, John Ioannis Stavroulakis
We obtain a quantitative form of Schur's comparison theorem for curves with finite total curvature in CAT(k) spaces. This sharpens and extends the classical arm and bow lemmas in E…
Total absolute curvature and rigidity of surfaces in Cartan-Hadamard manifolds
Mohammad Ghomi, Joseph Ansel Hoisington, Matteo Raffaelli +1
We show that closed surfaces with minimal total absolute curvature in Cartan-Hadamard 3-manifolds bound flat convex bodies. This generalizes Chern-Lashof's theorem for surfaces in…
Total curvature of convex hypersurfaces in Cartan-Hadamard manifolds
Mohammad Ghomi, John Ioannis Stavroulakis
We show that if the curvature of a Cartan-Hadamard -manifold is constant near a convex hypersurface , then the total Gauss-Kronecker curvature is not less th…
A local isoperimetric inequality for balls with nonpositive curvature
Mohammad Ghomi, John Ioannis Stavroulakis
We show that small perturbations of the metric of a ball in Euclidean n-space to metrics with nonpositive curvature do not reduce the isoperimetric ratio. Furthermore, the isoperim…
Dimension estimates for nonlinear nonautonomous systems in arbitrary normed spaces
John Ioannis Stavroulakis
We calculate explicit estimates for the dimension of trajectories satisfying a certain growth bound. We generalize the classic results of Kurzweil by considering nonlinear nonauton…
Towards a resolution of the Buchanan-Lillo conjecture
Elena Braverman, John Ioannis Stavroulakis
Buchanan and Lillo both conjectured that oscillatory solutions of the first-order delay differential equation with positive feedback , , where…
Semicycles and correlated asymptotics of oscillatory solutions to second-order delay differential equations
Elena Braverman, Alexander Domoshnitsky, John Ioannis Stavroulakis
We obtain several new comparison results on the distance between zeros and local extrema of solutions for the second order delay differential equation \begin{equation*} x^{\prime \…
Stability and oscillation of linear delay differential equations
John Ioannis Stavroulakis, Elena Braverman
There is a close connection between stability and oscillation of delay differential equations. For the first-order equation where i…