## About this book

### Introduction

This book is concerned with the study in two dimensions of stationary solutions of u_{ɛ} of a complex valued Ginzburg-Landau equation involving a small parameter ɛ. Such problems are related to questions occurring in physics, e.g., phase transition phenomena in superconductors and superfluids. The parameter ɛ has a dimension of a length which is usually small. Thus, it is of great interest to study the asymptotics as ɛ tends to zero.

One of the main results asserts that the limit u-star of minimizers u_{ɛ} exists. Moreover, u-star is smooth except at a finite number of points called defects or vortices in physics. The number of these defects is exactly the Brouwer degree – or winding number – of the boundary condition. Each singularity has degree one – or as physicists would say, vortices are quantized.

The limit u-star can also be viewed as a geometrical object. It is a minimizing harmonic map into S^{1} with prescribed boundary condition g. Topological obstructions imply that every map u into S^{1} with u = g on the boundary must have infinite energy. Even though u-star has infinite energy, one can think of u-star as having “less” infinite energy than any other map u with u = g on the boundary.

"...the book gives a very stimulating account of an interesting minimization problem. It can be a fruitful source of ideas for those who work through the material carefully."

- Alexander Mielke, *Zeitschrift für angewandte Mathematik und Physik 46*(5)

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### Bibliographic information

- DOI https://doi.org/10.1007/978-3-319-66673-0
- Copyright Information Springer International Publishing AG 2017
- Publisher Name Birkhäuser, Cham
- eBook Packages Mathematics and Statistics
- Print ISBN 978-3-319-66672-3
- Online ISBN 978-3-319-66673-0
- Series Print ISSN 2197-1803
- Series Online ISSN 2197-1811
- Buy this book on publisher's site