适合高年级本科水平阅读 弦理论入门教材 《A first course in string theory》2009第二版 作者：Barton Zwiebach（MIT麻省理工） 目录 Foreword by David Gross page xiii From the Preface to the First Edition xv Preface to the Second Edition xix Part I Basics 1 1 A brief introduction 3 1.1 The road to unification 3 1.2 String theory as a u