and Applied Analysis 3 capacity of the prey population x t is b/a, so it is meaningful that the economical threshold h is less than b/a. Thus, throughout this paper, we set up the following two assumptions: A1 D e < a b , A2 h ≤ b a . 2.1 From the biological point of view, it is reasonable that system 1.1 is considered to control the prey population in the biological meaning space { x, y : x ≥ ...

We describe a method for finding the families of relative equilibria of molecules which bifurcate from an equilibrium point as the angular momentum is increased from 0. Relative equilibria are steady rotations about a stationary axis during which the shape of the molecule remains constant. We show that the bifurcating families correspond bijectively to the critical points of a function h on the...

By this we mean that φ > 0 and φ ∈ C2(R3). It is a classical fact (see Coffman [Cof]) that such solutions exist and are unique for the cubic nonlinearity. Moreover, they are radial and smooth. Similar facts are known for more general nonlinearities, see e.g., Berestycki and Lions [BerLio] for existence and Kwon [Kwo] for uniqueness in greater generality. Clearly, ψ = eitα 2 φ solves (1). We see...

We show that the ground-state solitary waves of the critical nonlinear Schrödinger equation iψt(t, r)+ ψ+V ( r)|ψ |4/dψ = 0 in dimension d ≥ 2 are orbitally stable as → 0 if V (0)V (4)(0) < Gd [V ′′(0)]2, where Gd is a constant that depends only on d. © 2002 Elsevier Science B.V. All rights reserved.

The μ-Camassa-Holm (μCH) equation is a nonlinear integrable partial differential equation closely related to the Camassa-Holm equation. We prove that the periodic peaked traveling wave solutions (peakons) of the μCH equation are orbitally stable. AMS SUBJECT CLASSIFICATION (2000): 35Q35, 37K45.

Orbitally excited heavy-light mesons are potentially important as tools for tagging the flavors and momenta of ground-state pseudoscalars detected through weak decays. We use heavy-quark symmetry supplemented by insights gleaned from potential models to estimate masses and widths of p-wave B, Bs, and Ds mesons. We generalize these results to higher excitations. PACS numbers: 14.40.Jz, 13.25.+m,...

Mammalian cell cultures have become a major topic of research in the biopharmaceutical industry. This kind of cells require specific conditions to grow. In this thesis, we study the hydrodynamics of orbitally shaken reactors (OSR), a recently introduced kind of bioreactors for mammalian cell cultures that represents a simple to operate and cheap alternative to commonly used reactors such as sti...