The Hubble flow: an observer's perspective

Abstract

In this methodological note we discuss some details and peculiarities of the cosmic expansion as viewed by a realistic observer. We show that the velocity $v_{\Theta }$ related to a change (measured by observer's clock) of the angular distance, plays an important role in formation of a meaningful observed picture of the expansion of the universe. Usage of this velocity and the angular distance (in addition to the standard approach --- proper distance and corresponding velocity) allows to present the cosmic expansion in a more illustrative manner. These parameters play a key role in visualization of the expansion.

17 pages, original russian version is accepted to Physics Uspekhi vol. 57 (2014); references added, misprints corrected

References in corpus (2)

• Baryon Acoustic Oscillations in the Ly-α forest of BOSS quasars
• Objects Appear Smaller as They Recede: How Proper Motions Can Directly Reveal the Cosmic Expansion, Provide Geometric Distances, and Measure the Hubble Constant

Cited by in corpus (2)

• Unified approach to redshift in cosmological /black hole spacetimes and synchronous frame
• Velocities of distant objects in General Relativity revisited