Abstract A direct approach to perturbation theory for the nonlinear Schr?dinger equation is developed based on the separation of variables. The first-order effects of perturbation on a bright soliton, i.e. the slow time dependence of soliton parameters and the first-order correction are derived.
Received: 20 May 2004
Revised: 30 June 2004
Accepted manuscript online:
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
