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Updated: May 14, 2026
12:14
The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
New window into stochastic gravitational wave background
Aditya Rotti1, Tarun Souradeep
1IUCAA, Post Bag 4, Ganeshkhind, Pune 411007, India. aditya@iucaa.ernet.in
Physical Review Letters
|February 2, 2013
Summary
A stochastic gravitational wave background (SGWB) can lens cosmic microwave background (CMB) photons. Analyzing CMB polarization, particularly B modes, offers a path to detect SGWB and constrain its energy density.
Area of Science:
- Cosmology
- Astrophysics
- Gravitational Wave Astronomy
Background:
- A stochastic gravitational wave background (SGWB) is predicted by various cosmological models.
- This SGWB can gravitationally lens cosmic microwave background (CMB) photons, affecting their polarization.
Purpose of the Study:
- To correct existing literature for CMB polarization power spectra modifications due to gravitational wave lensing.
- To explore the potential of using CMB measurements to constrain the energy density of an SGWB.
Main Methods:
- Analyzing modifications to CMB polarization power spectra caused by weak gravitational lensing from SGWB.
- Investigating the mixing of E-mode and B-mode polarization power spectra.
- Utilizing current data from QUAD, WMAP, and ACT experiments.
Main Results:
- Gravitational wave lensing distorts all four CMB power spectra, most notably mixing E-mode and B-mode polarization.
- Current CMB temperature anisotropy power spectra provide the most stringent constraints on SGWB energy density (Ω(GW)).
Conclusions:
- Future improvements in B-mode polarization upper limits will yield more stringent bounds on Ω(GW).
- Detection of B-mode polarization exceeding predictions from large-scale structure lensing could indicate the presence of an SGWB.
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