0
2013
Impact Factor

# Andrey Shilnikov

10, Ulyanov Str, 603005 Nizhny Novgorod/
750 COE, 7th floor, 30 Pryor Street, 30303-3083, Atlanta, USA
Department of Differential Equations Research Institute for Applied Mathematics & Cybernetics of Nizhny Novgorod University/
Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia

## Publications:

 Afraimovich V. S., Gonchenko S. V., Lerman L. M., Shilnikov A. L., Turaev D. V. Scientific Heritage of L.P. Shilnikov 2014, vol. 19, no. 4, pp.  435-460 Abstract This is the first part of a review of the scientific works of L.P. Shilnikov. We group his papers according to 7 major research topics: bifurcations of homoclinic loops; the loop of a saddle-focus and spiral chaos; Poincare homoclinics to periodic orbits and invariant tori, homoclinic in noautonous and infinite-dimensional systems; Homoclinic tangency; Saddlenode bifurcation — quasiperiodicity-to-chaos transition, blue-sky catastrophe; Lorenz attractor; Hamiltonian dynamics. The first two topics are covered in this part. The review will be continued in the further issues of the journal. Keywords: Homoclinic chaos, global bifurcations, spiral chaos, strange attractor, saddle-focus, homoclinic loop, saddle-node, saddle-saddle, Lorenz attractor, hyperbolic set Citation: Afraimovich V. S., Gonchenko S. V., Lerman L. M., Shilnikov A. L., Turaev D. V.,  Scientific Heritage of L.P. Shilnikov, Regular and Chaotic Dynamics, 2014, vol. 19, no. 4, pp. 435-460 DOI:10.1134/S1560354714040017
 Belykh I., Jalil S., Shilnikov A. L. Burst-duration mechanism of in-phase bursting in inhibitory networks 2010, vol. 15, no. 2-3, pp.  146-158 Abstract We study the emergence of in-phase and anti-phase synchronized rhythms in bursting networks of Hodgkin–Huxley–type neurons connected by inhibitory synapses.We show that when the state of the individual neuron composing the network is close to the transition from bursting into tonic spiking, the appearance of the network’s synchronous rhythms becomes sensitive to small changes in parameters and synaptic coupling strengths. This bursting-spiking transition is associated with codimension-one bifurcations of a saddle-node limit cycle with homoclinic orbits, first described and studied by Leonid Pavlovich Shilnikov. By this paper, we pay tribute to his pioneering results and emphasize their importance for understanding the cooperative behavior of bursting neurons. We describe the burst-duration mechanism of inphase synchronized bursting in a network with strong repulsive connections, induced by weak inhibition. Through the stability analysis, we also reveal the dual property of fast reciprocal inhibition to establish in- and anti-phase synchronized bursting. Keywords: bursting neurons, synchronization, inhibitory networks, burst duration Citation: Belykh I., Jalil S., Shilnikov A. L.,  Burst-duration mechanism of in-phase bursting in inhibitory networks, Regular and Chaotic Dynamics, 2010, vol. 15, no. 2-3, pp. 146-158 DOI:10.1134/S1560354710020048
 Shilnikov A. L., Cymbalyuk G. Homoclinic bifurcations of periodic orbits en a route from tonic spiking to bursting in neuron models 2004, vol. 9, no. 3, pp.  281-297 Abstract The methods of qualitative theory of slow-fast systems applied to biophysically realistic neuron models can describe basic scenarios of how these regimes of activity can be generated and transitions between them can be made. We demonstrate how two different codimension-one bifurcations of a saddle-node periodic orbit with homoclinic orbits can explain transitions between tonic spiking and bursting activities in neuron models following Hodgkin–Huxley formalism. In the first case, we argue that the Lukyanov–Shilnikov bifurcation of a saddle-node periodic orbit with non-central homoclinics is behind the phenomena of bi-stability observed in a model of a leech heart interneuron under defined pharmacological conditions. This model can exhibit two coexisting types of oscillations: tonic spiking and bursting. Moreover, the neuron model can also generate weakly chaotic trains of bursting when a control parameter is close to the bifurcation value. In the second case, the transition is continuous and reversible due to the blue sky catastrophe bifurcation. This bifurcation provides a plausible mechanism for the regulation of the burst duration which may increases with no bound as $1/\sqrt{\alpha-\alpha_0}$, where $\alpha_0$ is the transitional value, while the inter-burst interval remains nearly constant. Citation: Shilnikov A. L., Cymbalyuk G.,  Homoclinic bifurcations of periodic orbits en a route from tonic spiking to bursting in neuron models, Regular and Chaotic Dynamics, 2004, vol. 9, no. 3, pp. 281-297 DOI:10.1070/RD2004v009n03ABEH000281
 Pisarevskii V., Shilnikov A. L., Turaev D. V. Asymptotic normal forms for equilibria with a triplet of zero characteristic exponents in systems with symmetry 1998, vol. 3, no. 1, pp.  19-27 Abstract Asymptotic normal forms for equilibria with a triplet of zero characteristic exponents in systems with $\mathbb{Z}_q$-symmetry are listed. Citation: Pisarevskii V., Shilnikov A. L., Turaev D. V.,  Asymptotic normal forms for equilibria with a triplet of zero characteristic exponents in systems with symmetry, Regular and Chaotic Dynamics, 1998, vol. 3, no. 1, pp. 19-27 DOI:10.1070/RD1998v003n01ABEH000058