This folder contains the movies of the time evolution of the Cosmological Collider signals, supplemental material of the following Letter:

• Denis Werth -- Sorbonne University, Institut d'Astrophysique de Paris (IAP)
• Lucas Pinol -- Instituto de Física Teórica (IFT) Madrid
• Sébastien Renaux-Petel -- CNRS, Institut d'Astrophysique de Paris (IAP)

We are interested in the three-point correlation function of the curvature perturbation in Fourier space, known as the bispectrum. Following standard conventions, we define the dimensionless shape function S such that

$$ \langle \zeta_{\vec{k}_ 1} \zeta_{\vec{k}_ 2} \zeta_{\vec{k}_ 3}\rangle' = \frac{(2\pi)^4}{(k_1 k_2 k_3)^2} \Delta_\zeta^4 S(k_1, k_2, k_3), $$

where $\Delta_\zeta^2 = \frac{k^3}{2\pi^2} \langle \zeta_{\vec{k}} \zeta_{-\vec{k}}\rangle'$ is the dimensionless power spectrum of the curvature perturbation. The movies below display the shape function as a function of time for the following Lagrangian

$$ \mathcal{L}/a^3 = -\frac{1}{2}(\partial_\mu \pi_c)^2 - \frac{1}{2}(\partial_\mu \sigma)^2 -\frac{1}{2}m^2\sigma^2 + \rho \dot{\pi}_c\sigma - \frac{1}{2}\alpha\dot{\pi}_c \sigma^2, $$

both for $\rho/H = 0.1$ (weak mixing) and $\rho/H = 5$ (strong mixing). We also define the effective frequency of the cosmological collider signal $\mu_{\rm{eff}}^2 = m_{\rm{eff}}^2/H^2 - 9/4$ with $m_{\rm{eff}}^2 = m^2 + \rho^2$.

For $\mu_{\rm{eff}} = 5, \rho/H = 0.1$

For $\mu_{\rm{eff}} = 5, \rho/H = 5$

Note that we have normalized the shape functions to unity in the equilateral configuration. The measure of time is expressed in number of efolds elapsed since Hubble horizon exit of the long mode.