Contents

1 Introduction

2 Coulomb Phases and Fibers

3 Rational Curves in Calabi–Yau Varieties

4 SU(5)×U(1) with 5 Matter

5 SU(5)×U(1) with 10 Matter

6 Flops and Rational Sections

7 Singlets

8 Co-dimension three Fibers and Yukawa Couplings

9 Multiple U(1)s and Higgsing

10 Discussion and Outlook