Results 21 to 30 of about 368,748 (292)
Non-equilibrium theory of the allele frequency spectrum [PDF]
, 2006 A forward diffusion equation describing the evolution of the allele frequency spectrum is presented. The influx of mutations is accounted for by imposing a suitable boundary condition.
Evans, Steven N. +2 more
core +2 more sources
Conditions for Oscillation of a Neutral Differential Equation
International Journal of Differential Equations, 2010 For a neutral differential equation with positive and changeable sign coefficients [x(t)−a(t)x(δ(t))]′+p(t)F(x(τ(t)))−q(t)G(x(σ(t)))=0, oscillation criteria are established, where q(t) is not required as nonnegative. Several new results are obtained.
Weiping Yan, Jurang Yan
doaj +1 more source
Periodic solutions of a neutral impulsive differential equation
上海师范大学学报. 自然科学版, 2017 In this paper, we consider a neutral impulsive differential equation. An impulsive predatorprey model with non-monotonic functional response is investigated. Some novel sufficient conditions are obtained for the nonexistence of periodic solutions and the
Hu Mi, Xia Yonghui
doaj +1 more source
Oscillations in Higher-Order Neutral Differential Equations
Canadian Journal of Mathematics, 1993 AbstractConsider the n-th order (n ≥ 1 ) neutral differential equation where σ1 < σ 2 < ∞ and μ and η are increasing real-valued functions on [Ƭ1, Ƭ2] and [σ1, σ2] respectively. The function μ is assumed to be not constant on [Ƭ1, Ƭ2] and [Ƭ1, Ƭ2] for every Ƭ ∈ (Ƭ1, Ƭ2) similarly, for each σ ∈ (σ1, σ2), it is supposed that r\ is not constant on
Philos, C. G. +2 more
openaire +3 more sources
Knizhnik-Zamolodchikov equation and extended symmetry for stable Hall states [PDF]
, 1995 We describe a $n$ component abelian Hall fluid as a system of {\it composite bosons} moving in an average null field given by the external magnetic field and by the statistical flux tubes located at the position of the particles.
De Martino, A., Musto, R
core +2 more sources
Impulsive partial neutral differential equations
Applied Mathematics Letters, 2006 The authors establish conditions for the existence of mild and strong solutions of a partial neutral functional-differential equation with unbounded delay of the form \[ (d/dt)(x(t)+F(t, x_t)) = Ax(t)+G(t, x_t) \] subject to pre-assigned moments of impulse effects.
Hernandez, E, Henriquez, HR
openaire +3 more sources
Martingale Option Pricing [PDF]
, 2007 We show that our generalization of the Black-Scholes partial differential equation (pde) for nontrivial diffusion coefficients is equivalent to a Martingale in the risk neutral discounted stock price.
Bassler, K. E. +2 more
core +2 more sources
Oscillation of nonlinear neutral delay differential Equations [PDF]
Journal of Applied Mathematics and Computing, 2006 Sufficient conditions for the oscillation of the first-order nonlinear neutral delay differential equation \[ [x(t)-q(t)x(t-\sigma)]'+f(t,x(\tau(t)))=0 \] are given. The results obtained improve and extend some known results. One example is given to illustrate the results.
Elabbasy, Elmetwally M. +2 more
openaire +1 more source
Electronic Journal of Qualitative Theory of Differential Equations, 2021 This paper examines the oscillatory behavior of solutions to a class of third-order differential equations with bounded and unbounded neutral coefficients. Sufficient conditions for all solutions to be oscillatory are given.
Ercan Tunç +3 more
doaj +1 more source
Oscillatory and asymptotic behavior of a third-order nonlinear neutral differential equation [PDF]
Opuscula Mathematica, 2017 This paper discusses oscillatory and asymptotic properties of solutions of a class of third-order nonlinear neutral differential equations. Some new sufficient conditions for a solution of the equation to be either oscillatory or to converges to zero are
John R. Graef +2 more
doaj +1 more source