English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We use the ACTpol published cosmic microwave background (CMB) polarizationdata to constrain cosmological birefringence, a tracer of parity violationbeyond the standard model of particle physics. To this purpose, we employ allthe polarized ACTpol spectra, including the cross-correlations betweentemperature anisotropy and B mode polarization (TB) and between E mode and Bmode (EB), which are most sensitive to the effect. We build specific, so-calledD-estimators for birefringence and assess their performances and error budgetsby using realistic Monte Carlo simulations based on the experimentalcharacteristics provided by the ACTpol collaboration. We determine the optimalmultipole range for our analysis to be $250 < \ell < 3025$ over which we find anull result for the uniform birefringence angle $\alpha = 0.29^\circ \pm0.28^\circ$ (stat.) $\pm 0.5^\circ$ (syst.), the latter uncertainty being theestimate published by the ACTpol team on their global systematic error budget.We show that this result holds consistently when other multipole ranges areconsidered. Finally, we forecast the capability of several forthcoming groundbased, balloon and space borne CMB experiments to constrain the birefringenceangle, showing, e.g., that the proposed post-Planck COrE satellite missioncould in principle constrain $\alpha$ at a level of 10 arcsec, provided thatall systematics are under control. Under the same circumstances, we find theCOrE constraints to be at least 2 or 3 times better than what could ideally beachieved by the other experiments considered.

Constraints on parity violation from ACTpol and forecasts for forthcoming CMB experiments