Lensing-induced morphology changes in CMB temperature maps in modified gravity theories

Understand

Lensing of the Cosmic Microwave Background (CMB) changes the morphology of pattern of temperature fluctuations, so topological descriptors such as Minkowski Functionals can probe the gravity model responsible for the lensing.

• We show how the recently introduced two-to-two and three-to-one kurt-spectra (and their associated correlation functions), which depend on the power spectrum of the lensing potential, can be used to probe modified gravity theories such as $f({R})$ theories of gravity and quintessence models.
• We also investigate models based on effective field theory, which include the constant-$\Omega$ model, and low-energy Ho\vrava theories.
• Estimates of the cumulative signal-to-noise for detection of lensing-induced morphology changes, reaches ${\cal O}(10^3)$ for the future planned CMB polarization mission COrE$^{+}$.