Primordial Gravitational Waves and Cosmic Microwave Background Radiation

TL;DR

This paper reviews recent theoretical and observational progress in detecting primordial gravitational waves through their influence on the cosmic microwave background, highlighting promising indications and future prospects.

Contribution

It summarizes advancements in theory and observations related to primordial gravitational waves and their potential detection via CMB anisotropies.

Findings

Indications of gravitational wave contributions to CMB anisotropies

Ongoing observational efforts aim to confirm detections

Progress achieved in both theoretical understanding and observational techniques

Abstract

This is a summary of presentations delivered at the OC1 parallel session "Primordial Gravitational Waves and the CMB" of the 12th Marcel Grossmann meeting in Paris, July 2009. The reports and discussions demonstrated significant progress that was achieved in theory and observations. It appears that the existing data provide some indications of the presence of gravitational wave contribution to the CMB anisotropies, while ongoing and planned observational efforts are likely to convert these indications into more confident statements about the actual detection.