Robust forecasts on fundamental physics from the foreground-obscured, gravitationally-lensed CMB polarization
By J. Errard, S. Feeney, Hiranya V. Peiris, Andrew H. Jaffe. 2015
150 citations recorded by the source corpus.
Recent results from the BICEP, Keck Array and Planck Collaborations demonstrate that Galactic foregrounds are an unavoidable obstacle in the search for evidence of inflationary gravitational waves in the cosmic microwave background (CMB) polarization. Beyond the foregrounds, the effect of lensing by intervening large-scale structure further obscures all but the strongest inflationary signals permitted by current data. With a plethora of ongoing and upcoming experiments aiming to measure these signatures, careful and self-consistent consideration of experiments' foreground- and lensing-removal capabilities is critical in obtaining credible forecasts of their performance. We investigate the capabilities of instruments such as Advanced ACTPol, BICEP3 and Keck Array, CLASS, EBEX10K, PIPER, Simons Array, SPT-3G and SPIDER, and projects as COrE+, LiteBIRD-ext, PIXIE and Stage IV, to clean contamination due to polarized synchrotron and dust from raw multi-frequency data, and remove lensing from the resulting co-added CMB maps (either using iterative CMB-only techniques or through cross-correlation with external data). Incorporating these effects, we present forecasts for the constraining power of these experiments in terms of inflationary physics, the neutrino sector, and dark energy parameters. Made publicly available through an online interface, this tool enables the next generation of CMB experiments to foreground-proof their designs, optimize their frequency coverage to maximize scientific output, and determine where cross-experimental collaboration would be most beneficial. We find that analyzing data from ground, balloon and space instruments in complementary combinations can significantly improve component separation performance, delensing, and cosmological constraints over individual datasets. In particular, we find that a combination of post-2020 ground- and space-based experiments could achieve constraints such as σ(r)∼1.3×10−4, σ(nt)∼0.03, σ( ns )∼1.8×10−3, σ(αs)∼1.7×10−3, σ( Mν )∼31 meV, σ( w )∼0.09, σ( w0 )∼ 0.25, 0σ( wa )∼ 0.5, σ( Neff )∼0.024 and σ( Ωk )∼1.5×10−3, after component separation and iterative delensing.
Subfields: Artificial Intelligence, Astronomy and Astrophysics, Instrumentation
View Paper: https://www.semanticscholar.org/paper/ebc1156df05da2574313711c07cadc11bdf872d6
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Citations in the corpus
- Standard Model—axion—seesaw—Higgs portal inflation. Five problems of particle physics and cosmology solved in one stroke (2016, background): “Although this is beyond the current accuracy of global fits to cosmological data, it may however be reached in the next decade by a stage-IV CMB polarisation experiment [182,183].”
- PICO: Probe of Inflation and Cosmic Origins (2019, background): “• Analytic Forecast The analytic forecast relies on an established, documented, publicly available, cosmological parameters forecasting code [225].”
- CMB-S4: Forecasting Constraints on Primordial Gravitational Waves (2020, result): “This also differentiates our current approach from forecasts other groups have made for CMB-S4 prior to the formal existence of our collaboration (Wu et al. 2014; Errard et al. 2016; Barron et al. 2018).”
- Exploring cosmic origins with CORE: Inflation (2016, methodology): “As an approximate idea of the impact of foreground uncertainties, let us note that a Fisher matrix approach including foreground residuals and delensing [168] leads to an uncertainty on the tensor-to-scalar ratio as σ(r) ≈ 3.”