Weak Lensing Minima and Peaks: Cosmological Constraints and the Impact of Baryons. (arXiv:1910.04171v1 [astro-ph.CO])

<a href="http://arxiv.org/find/astro-ph/1/au:+Coulton_W/0/1/0/all/0/1">William R. Coulton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_J/0/1/0/all/0/1">Jia Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McCarthy_I/0/1/0/all/0/1">Ian G. McCarthy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Osato_K/0/1/0/all/0/1">Ken Osato</a>

We present a novel statistic to extract cosmological information in weak

lensing data: the lensing minima. We also investigate the effect of baryons on

the cosmological constraints from peak and minimum counts. Using the

texttt{MassiveNuS} simulations, we find that lensing minima are sensitive to

non-Gaussian cosmological information and are complementary to the lensing

power spectrum and peak counts. For an LSST-like survey, we obtain $95%$

credible intervals from a combination of lensing minima and peaks that are

significantly stronger than from the power spectrum alone, by $44%$, $11%$,

and $63%$ for the neutrino mass sum $sum m_nu$, matter density $Omega_m$,

and amplitude of fluctuation $A_s$, respectively. We explore the effect of

baryonic processes on lensing minima and peaks using the hydrodynamical

simulations texttt{BAHAMAS} and texttt{Osato15}. We find that ignoring

baryonic effects would lead to strong ($approx 4 sigma$) biases in inferences

from peak counts, but negligible ($approx 0.5 sigma$) for minimum counts,

suggesting lensing minima are a potentially more robust tool against baryonic

effects. Finally, we demonstrate that the biases can in principle be mitigated

without significantly degrading cosmological constraints when we model and

marginalize the baryonic effects.

We present a novel statistic to extract cosmological information in weak

lensing data: the lensing minima. We also investigate the effect of baryons on

the cosmological constraints from peak and minimum counts. Using the

texttt{MassiveNuS} simulations, we find that lensing minima are sensitive to

non-Gaussian cosmological information and are complementary to the lensing

power spectrum and peak counts. For an LSST-like survey, we obtain $95%$

credible intervals from a combination of lensing minima and peaks that are

significantly stronger than from the power spectrum alone, by $44%$, $11%$,

and $63%$ for the neutrino mass sum $sum m_nu$, matter density $Omega_m$,

and amplitude of fluctuation $A_s$, respectively. We explore the effect of

baryonic processes on lensing minima and peaks using the hydrodynamical

simulations texttt{BAHAMAS} and texttt{Osato15}. We find that ignoring

baryonic effects would lead to strong ($approx 4 sigma$) biases in inferences

from peak counts, but negligible ($approx 0.5 sigma$) for minimum counts,

suggesting lensing minima are a potentially more robust tool against baryonic

effects. Finally, we demonstrate that the biases can in principle be mitigated

without significantly degrading cosmological constraints when we model and

marginalize the baryonic effects.

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