@article{17666,
  abstract     = {We have investigated a recently proposed halo-based model, Camelus, for predicting weak-lensing peak counts, and compared its results over a collection of 162 cosmologies with those from N-body simulations. While counts from both models agree for peaks with S/N>1 (where S/N is the ratio of the peak height to the r.m.s. shape noise), we find ≈50% fewer counts for peaks near S/N=0 and significantly higher counts in the negative S/N tail. Adding shape noise reduces the differences to within 20% for all cosmologies. We also found larger covariances that are more sensitive to cosmological parameters. As a result, credibility regions in the {Ωm,σ8} are ≈30% larger. Even though the credible contours are commensurate, each model draws its predictive power from different types of peaks. Low peaks, especially those with 2<S/N<3, convey important cosmological information in N-body data, as shown in \cite{DietrichHartlap, Kratochvil2010}, but \textsc{Camelus} constrains cosmology almost exclusively from high significance peaks (S/N>3). Our results confirm the importance of using a cosmology-dependent covariance with at least a 14\% improvement in parameter constraints. We identified the covariance estimation as the main driver behind differences in inference, and suggest possible ways to make Camelus even more useful as a highly accurate peak count emulator.},
  author       = {Zorrilla Matilla, José Manuel and Haiman, Zoltán and Hsu, Daniel and Gupta, Arushi and Petri, Andrea},
  issn         = {2470-0010},
  journal      = {Physical Review D},
  number       = {8},
  publisher    = {American Physical Society},
  title        = {{Do dark matter halos explain lensing peaks?}},
  doi          = {10.1103/physrevd.94.083506},
  volume       = {94},
  year         = {2016},
}

@article{17669,
  abstract     = {Unprecedentedly precise cosmic microwave background (CMB) data are expected from ongoing and near-future CMB Stage-III and IV surveys, which will yield reconstructed CMB lensing maps with effective resolution approaching several arcminutes. The small-scale CMB lensing fluctuations receive non-negligible contributions from nonlinear structure in the late-time density field. These fluctuations are not fully characterized by traditional two-point statistics, such as the power spectrum. Here, we use N-body ray-tracing simulations of CMB lensing maps to examine two higher-order statistics: the lensing convergence one-point probability distribution function (PDF) and peak counts. We show that these statistics contain significant information not captured by the two-point function, and provide specific forecasts for the ongoing Stage-III Advanced Atacama Cosmology Telescope (AdvACT) experiment. Considering only the temperature-based reconstruction estimator, we forecast 9σ (PDF) and 6σ (peaks) detections of these statistics with AdvACT. Our simulation pipeline fully accounts for the non-Gaussianity of the lensing reconstruction noise, which is significant and cannot be neglected. Combining the power spectrum, PDF, and peak counts for AdvACT will tighten cosmological constraints in the Ωm-σ8 plane by ≈30%, compared to using the power spectrum alone.},
  author       = {Liu, Jia and Hill, J. Colin and Sherwin, Blake D. and Petri, Andrea and Böhm, Vanessa and Haiman, Zoltán},
  issn         = {2470-0010},
  journal      = {Physical Review D},
  number       = {10},
  publisher    = {American Physical Society},
  title        = {{CMB lensing beyond the power spectrum: Cosmological constraints from the one-point probability distribution function and peak counts}},
  doi          = {10.1103/physrevd.94.103501},
  volume       = {94},
  year         = {2016},
}