Bulletin of the American Physical Society
2017 Annual Spring Meeting of the APS Ohio-Region Section
Volume 62, Number 6
Friday–Saturday, May 5–6, 2017; Ypsilanti, Michigan
Session D2: Contributed: Computational Physics |
Hide Abstracts |
Chair: Jonathan Skuza, Eastern Michigan University Room: Pray-Harrold 302 |
Saturday, May 6, 2017 8:36AM - 8:48AM |
D2.00001: Emergent stochastic oscillations and signal detection in tree networks of excitable elements Ali Khaledi Nasab, Justus kromer, Lutz Schimansky-Geier, Alexander Neiman We study the stochastic dynamics of strongly-coupled excitable elements on a tree network. The peripheral nodes receive independent random inputs which may induce large spiking events propagating through the branches of the tree and leading to global coherent oscillations in the network. This scenario may be relevant to action potential generation in certain sensory neurons, which possess myelinated distal dendritic tree-like arbors with excitable nodes of Ranvier at peripheral and branching nodes and exhibit noisy periodic sequences of action potentials.We focus on the spiking statistics of the central node, which fires in response to a noisy input at peripheral nodes. We show that, in the strong coupling regime, relevant to myelinated dendritic trees, the spike train statistics can be predicted from an isolated excitable element with rescaled parameters according to the network topology. Furthermore, we show that by varying the network topology the spike train statistics of the central node can be tuned to have a certain firing rate and variability or to allow for an optimal discrimination of inputs applied at the peripheral nodes. [Preview Abstract] |
Saturday, May 6, 2017 8:48AM - 9:00AM |
D2.00002: Flux-Dependent Circular Currents in a Meta-Connected Nano-Ring Eric Hedin, Yong Joe We consider electron transmission properties of a nano-scale ring structure with six embedded quantum dots (QDs). This system can represent a molecular benzene ring structure, which we analyze in the meta configuration (asymmetric system-leads coupling) using a tight-binding model of the Schr\"{o}dinger equation. Non-classical circular ring probability currents manifest primarily as Fano-type resonances at electron energy values corresponding to double poles in the transmission amplitude. The position and resonance structure of these circular currents shows strong dependence upon the value of the external flux through the ring. Computational results allow us to analyze and compare the overall transmission and circular transmission as a function of flux and the zero-pole configuration of the transmission amplitude as shown in complex energy plane contour plots. [Preview Abstract] |
Saturday, May 6, 2017 9:00AM - 9:12AM |
D2.00003: Reversible island nucleation and growth with anomalous diffusion Ehsan Sabbar, Jacques Amar Motivated by recent experiments on submonolayer organic film growth with anomalous diffusion, a general rate-equation (RE) theory of submonolayer island nucleation and growth was developed [J.G. Amar and M. Semaan, Phys. Rev. E {\bf 93}, 062805 (2016)] which takes into account the critical island-size $i$, island fractal dimension $d_f$, substrate dimension $d$, and diffusion exponent $\mu$,and good agreement with simulations was found for the case of irreversible growth corresponding to a critical island-size $i = 1$ with $d = 2$.However, since many experiments correspond to a critical island-size larger than $1$, it is of interest to determine if the RE predictions also hold in the case of reversible island nucleation with anomalous diffusion.Here we present the results of simulations of submonolayer growth with $i = 2$ ($d = 2$)which were carried out for both the case of superdiffusion ($\mu > 1$) and subdiffusion ($\mu < 1$) as well as for both ramified islands ($d_f \simeq 2$) and point-islands ($d_f = \infty)$. In the case of superdiffusion,excellent agreement is obtained with the RE theory for the exponents $\chi(\mu)$ and $\chi_1(\mu)$ .In the case of subdiffusion we find only partial agreement with the RE theory for the case $i = d = 2$. [Preview Abstract] |
Saturday, May 6, 2017 9:12AM - 9:24AM |
D2.00004: Effect of receptor potential on mechanical oscillations in a model of sensory hair cell Mahvand Khamesian, Alexander B. Neiman Hair cells mediating the senses of hearing and balance rely on active mechanisms for amplification of mechanical signals. In amphibians, hair cells exhibit spontaneous self-sustained mechanical oscillations of their hair bundles. We study the response of the mechanical oscillations to perturbation of the cell's membrane potential in a model for hair bundle of bullfrog saccular hair cells. We identify bifurcation mechanism leading to mechanical oscillations using the membrane potential and the strength of fast adaptation as control parameters and then compute static and dynamic sensitivity of mechanical oscillations to voltage variations. We show that fast adaptation results in the static sensitivity of oscillating hair bundles in the range 0.1 -- 0.2~nm/mV, consistent with recent experimental work. Predicted dynamic response of oscillating hair bundle to voltage variations is characterized by the values of sensitivity of up to 2~nm/mV, enhanced by the presence of fast adaptation. [Preview Abstract] |
Saturday, May 6, 2017 9:24AM - 9:36AM |
D2.00005: The Search for Type Ia Supernova Near Ultra-Violet (NUV) Subclasses Jake Miller, David Cinabro, Richard Kessler, Dan Scolnic, Ashley Li Type Ia Supernovas (SNIa) are very bright standardizable candles that can be used to measure cosmological parameters. A recent observation by Milne and collaborators claims that there are two classes of SNIa distinguished by their peak brightness in the ultraviolet, and that cosmological parameters measured with SNIa are severely biased unless the two classes are treated separately. We search for evidence for two classes of SNIa in archived SNIa data from the Sloan Digital Sky Survey (SDSS) and the SuperNova Legacy Survey (SNLS) comparing to a model of the Milne claim and a model with a single, broad distribution of SNIa peak ultraviolet brightnesses. The SNLS data supports a single single class of SNIa while the SDSS data is unable to distinguish between the two models. We see no evidence in support of the Milne and collaborators claim for two classes of SNIa. \newline [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700