1810.02441
Dark Energy Survey Year 1 Results: Cross-correlation between DES Y1 galaxy weak lensing and SPT+Planck CMB weak lensing
Omori, et al
Cross-correlate galaxy weak lensing measurements from DES Y1 data with a CMB weak lensing map derived from SPT and Planck data, with an effective overlapping area of 1289 deg^2. With the combined measurements from 4 source galaxy redshift bins, reject the hypothesis of no lensing wit ha significance of 10.8 sigma. When employing angular scale cuts, the significance is reduced to 6.8 sigma, which remains the highest S/N measurement of its kind to date. Fit the amplitude of the correlation functions while fixing the cosmo parameters to a fiducial LCDM model, finding A=0.99±0.17. Additionally use the correlation function meausremetns to constrain shear calibration bias, obtaining constraints that are consistent with previous DES analyses. Finally, when performing a cosmological analysis under the LCDM model, obtain the marginalized constraints of Omega_m=0.261+0.070-0.051 and S_8==sigma_8 sqrt(Omega_m/0.3)=0.660+0.085-0.100. These measurements are used in a companion work that presents cosmological constraints from the joint analysis of 2pt functions among galaxies, galaxy shears, and CMB lensing using DES, SPT and Planck data.
1810.03363
Nonscanning large-area Raman imaging for ex vivo/in vivo skin cancer discrimination
Schmälzin, et al
Imaging Raman spectroscopy can be used to identify cancerous tissue. Traditionally, a step-by-step scanning of the sample if applied to generate a Raman image, which, however, is too slow for routine examination of patients. By transferring the technique of integral field spectroscopy (IFS) from astronomy to Raman imaging, it becomes possible to record entire Raman images quickly within a single exposure, without the need for a tedious scanning procedure. An IFS-based Raman imaging setup is presented, which is capable of measuring skin ex vivo or in vivo. It is demonstrated how Raman images of healthy and cancerous skin biopsies were recorded and analyzed.
1810.03526
Seven problems with the claims related to the Hubble tension in arXiv:1810.02595
Riess, et al
Shanks+(2018) arXiV:1810.02595 make two claims that they argue bring the local measurement and early Universe prediction of H0 into agreement: A) they claim that Gaia DR2 parallax measurements show the geometric calibration of the Cepheid distance scale used to measure H0 to be grossly in error and B) that we live near the middle of an enormous void, further biasing the local measurement of the Hubble constant. Show that the first claim is caused by 5 erroneous uses of the data: in decreasing order of importance: 1) the use of a distance indicator, main sequence fitting of cluster stars, which is unrelated to the calibration of Cepheids and therefore has no bearing on current measurements of H0; 2) the use of Gaia data for Cepheids that fully saturate the detector, producing unreliable parallaxes; 3) the use of a fixed parallax offset which is known to depend on source magnitude and color but which is derived for sources with extremely different colors and magnitudes; 4) ignoring the uncertainty in this offset; and 5) ignoring the other geometric sources of Cepheid calibration, the distance of the LMC for detected eclipsing binaries and the masers in NGC 4258, which are independent of MW parallaxes. Just resolving the first 2 of these issues by not using unrelated or saturated data leads to no inconsistency between Gaia parallaxes and the current Cepheid distance scale. The second claim can be refuted 6) because of the increase in chi-squared that the alleged void would entail in SN measurement in the Hubble flow, and 7) because it would represent a 6 sigma fluctuation of cosmic variance between the local and globally measured expansion, requiring us to live in an exceedingly special location.
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