Back to the article index


Article Contents

ABSTRACT

1.INTRODUCTION

2.EXPANSION OF THE UNIVERSE: THE COSMOLOGICAL CONTEXT

3.MEASUREMENT OF DISTANCES
3.1.Cepheid Distance Scale
3.2.Tip of the Red Giant Branch (TRGB) Method
3.3.Maser Galaxies
3.4.Surface Brightness Fluctuation (SBF) Method
3.5.Tully-Fisher Relation
3.6.Type Ia Supernovae

4.THE HUBBLE SPACE TELESCOPE (HST) KEY PROJECT
4.1.Systematics on Ho at the End of the Key Project and a Decade Later

5.OTHER METHODS FOR DETERMINING Ho
5.1.Gravitational Lens Time Delays and Ho
5.2.The Sunyaev-Zel'dovich (SZ) Effect and Ho
5.3.Measurements of Anisotropies in the Cosmic Microwave Background

6.AGE OF THE UNIVERSE

7.WHY MEASURE Ho TO HIGHER ACCURACY?
7.1.Constraints on Dark Energy
7.2.Constraints on the Neutrino Mass
7.3.Measuring Ho to ± 2%

8.FUTURE IMPROVEMENTS

9.SUMMARY POINTS

10.DISCLOSURE STATEMENT

REFERENCES