Results 221 to 230 of about 48,052 (261)

Focusing nonlinear schrödinger equation and wave-packet collapse

Nonlinear Analysis: Theory, Methods & Applications, 1997
This paper is concerned with the Cauchy problem of the nonlinear Schrödinger equation (NLS) \[ i\psi_t+\Delta\psi+\sigma |\psi|^2 \psi=0,\quad x\in \mathbb{R}^d,\quad \psi(x,0)=\psi_0(x),\tag{1} \] with cubic nonlinearity and \(\sigma=1\). This is an important paradigm for the envelope dynamics of a weakly nonlinear wave-pocket propagating in a ...
Catherine Sulem
exaly   +2 more sources

A differential equation for the classical collapse problem

Astrophysics and Space Science, 1978
The classical gravitational collapse problem is analysed on the basis of an integral equation connecting the evolutionary time (defined as dt/d log ϱ) with the density ϱ and the ‘collapse function’ α, or by an equivalent first-order non-linear differential equation. The general behaviour of solutions is discussed, and some particular cases are studied.
Paolo Paolicchi, Paolicchi Paolo
exaly   +3 more sources

Equation of state in the gravitational collapse of stars

Nuclear Physics A, 1979
Abstract The equation of state in stellar collapse is derived from simple considerations, the crucial ingredient being that the entropy per nucleon remains small, of the order of unity (in units of k), during the entire collapse. In the early regime, ρ∼1010−1013 g/cm3, nuclei partially dissolve into α-particles and neutrons; the α-particles go back ...
H. A. BETHE   +3 more
openaire   +1 more source

Equations to Calculate Collapse Strength for High Collapse Casing

Journal of Pressure Vessel Technology, 2013
As wells are drilled deeper, the external pressures applied to well casing become greater. Conventional America Petroleum Institute (API) casing strength cannot meet the strength criteria of high pressure, high temperature, and high H2S (HPHTHS) gas wells which are called “3-high” gas wells.
Yuanhua Lin   +7 more
openaire   +1 more source

Collapse in the nonlinear Schrödinger equation

Journal of Experimental and Theoretical Physics, 1999
A new class of exact solutions with a singularity at finite time (collapse) is obtained for the nonlinear Schrodinger equation.
Yu. N. Ovchinnikov, I. M. Sigal
openaire   +1 more source

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