Day 1493

Tuesday.

1810.11030
Distinguishing standard and modified gravity cosmologies with machine learning
Peel, et al

Present a convolutional neural network to identify distinct cosmological scenarios based on the weak-lensing maps they produce.  Modified gravity models with massive neutrinos can mimic the standard concordance model in terms of Gaussian weak-lensing observables, limiting a deeper understanding of what causes cosmic acceleration.  Demonstrate that a network trained on simulated clean convergence maps, condensed into a novel representation, can discriminate between such degenerate models with 83%-100% accuracy.  The method outperforms conventional statistics by up to 40% and is more robust to noise.


1810.11658
Dark energy versus modified gravity: impacts on measuring neutrino mass
Zhao, et al

Compare the impacts of smooth dark energy, modified gravity, and interacting dark energy on the cosmological limits on the total mass of active neutrinos.  Consider the wCDM model, the f(R) model, and the interacting vacuum energy models with the forms of Q=beta H rho_Lambda and Q=beta Rho_c.  In the cosmological fits, use the Planck 2015 temperature and polarization data, in combination with other low-redshift observations, including the baryon acoustic oscillations, type Ia SNe, and the Hubble constant measurement, as well as the large-scale structure observations involving weak lensing and redshift-space distortion.  The Planck lensing measurement is also employed.  Find that, compared to the LCDM model, the wCDM model favors a higher upper limit on neutrino mass.  The f(R) model has a quite consistent neutrino mass with that in LCDM.  For the interacting dark energy model, the Q=beta H rho_c model favors a higher upper limit on neutrino mass, but the Q=beta H rho_Lambda model gives an identical neutrino mass with the case of LCDM.  Looking at the correlation between the model parameter and the neutrino mass, find that only when the model parameter is correlated with the neutrino mass, the model would have a significant influence on the measurement of the neutrino mass, otherwise the values of the neutrino mass are largely consistent with that given by LCDM.