insu-03644760
https://insu.hal.science/insu-03644760
https://insu.hal.science/insu-03644760/document
https://insu.hal.science/insu-03644760/file/PhysRevD.91.043534.pdf
arxiv:1412.3461
doi:10.1103/PhysRevD.91.043534
[INSU] INSU - Institut National des Sciences de l'Univers
[CNRS] CNRS - Centre national de la recherche scientifique
[IAP] Institut d'Astrophysique de Paris
[SORBONNE-UNIVERSITE] Sorbonne Université
[SU-INF-2018] SORBONNE université <2018
[SU-SCIENCES] Faculté des Sciences de Sorbonne Université
[SU-TI] Sorbonne Université - Texte Intégral
[ALLIANCE-SU] Alliance Sorbonne Université
Optimal estimator for resonance bispectra in the CMB
Münchmeyer, Moritz
Meerburg, P. Daniel
Wandelt, Benjamin D.
[SDU] Sciences of the Universe [physics]
ART
98.80.-k
98.80.Cq
98.80.Es
Cosmology
Particle-theory and field-theory models of the early Universe
Observational cosmology
Astrophysics - Cosmology and Nongalactic Astrophysics
We propose an (optimal) estimator for a CMB bispectrum containing logarithmically spaced oscillations. There is tremendous theoretical interest in such bispectra, and they are predicted by a plethora of models, including axion monodromy models of inflation and initial state modifications. The number of resolved logarithmical oscillations in the bispectrum is limited due to the discrete resolution of the multipole bispectrum. We derive a simple relation between the maximum number of resolved oscillations and the frequency. We investigate several ways to factorize the primordial bispectrum, and conclude that a one-dimensional expansion in the sum of the momenta ∑k<SUB>i</SUB>=k<SUB>t</SUB> is the most efficient and flexible approach. We compare the expansion to the exact result in multipole space and show for ω<SUB>eff</SUB>=100 that O (1 0<SUP>3</SUP>) modes are sufficient for an accurate reconstruction. We compute the expected σ<SUB>f<SUB>NL</SUB></SUB> and find that within an effective field theory (EFT) the overall signal to noise scales as S /N ∝ω<SUP>3 /2</SUP>. Using only the temperature data we find S /N ∼O (1 - 1 0<SUP>2</SUP>) for the frequency domain set by the EFT.
2015
2022-04-29
en
Physical Review D