I. INTRODUCTION

II. B MODES AND WEAK LENSING

III. THE CMB POTENTIAL ESTIMATOR
A. The ideal case
B. The effect of Shape Noise
C. The CMB Lensing Potential Estimator for Fiducial Surveys

IV. DETECTING THE TENSOR-TO-SCALAR RATIO
A. The Null-Hypothesis Test
B. Results
C. Related Work in the Literature

V. CONCLUSIONS