Polytropic Equilibrium. I. The Radii of Configurations Under Given External Pressure

Pressure effects on the equilibrium configurations of bilayer lipid membranes

Planar bilayer lipid membranes (BLMs) are currently employed to construct many bio-inspired material systems and structures. In order to characterize the pressure effects on the equilibrium configurations of these biological membranes, a novel continuum model is proposed. The BLM is assumed to be a two-layer smectic A liquid crystal. The mean orientation of the amphiphilic molecules comprising ...

Post-Newtonian treatment of bar mode instability in rigidly rotating equilibrium configurations for polytropic stars

In this paper we determine the onset point of secular instability for the nonaxisymmetric bar mode in rigidly rotating equilibrium configurations in the PostNewtonian approximation, in order to apply it to neutron stars. The treatment is based on a precedent Newtonian analytic energy variational method which we have extended to the Post-Newtonian case. This method, based upon Landau’s theory of...

Dynamical configurations and bistability of helical nanostructures under external torque.

We study the motion of a ferromagnetic helical nanostructure under the action of a rotating magnetic field. A variety of dynamical configurations were observed that depended strongly on the direction of magnetization and the geometrical parameters, which were also confirmed by a theoretical model, based on the dynamics of a rigid body under Stokes flow. Although motion at low Reynolds numbers i...

Ela on the Spectral Radii of Graphs without given Cycles

Let G be a graph with n vertices and ρ(G) be the spectral radius of its adjacency matrix. Write Cl for the cycle of order l and let gl(n) = max{ρ(G) : |V (G)| = n, neither Cl nor Cl+1 is a subgraph of G}. This paper obtains the exact value of g5(n) with the unique extremal graph.

On the spectral radii of graphs without given cycles