Wenjuan Fang, Baojiu Li, Gong-Bo Zhao

The morphological properties of large scale structure of the Universe can be fully described by four Minkowski functionals (MFs), which provide important complementary information to other statistical observables such as the widely used 2-point statistics in configuration and Fourier spaces. In this work, for the first time, we present the differences in the morphology of large scale structure caused by modifications to general relativity (to address the cosmic acceleration problem), by measuring the MFs from N-body simulations of modified gravity and general relativity. We find strong statistical power when using the MFs to constrain modified theories of gravity: with a galaxy survey that has survey volume $\sim 0.125 (h^{-1}$Gpc$)^3$ and galaxy number density $\sim 1 / (h^{-1}$Mpc$)^{3}$, the two normal-branch DGP models and the F5 $f(R)$ model that we simulated can be discriminated from $\Lambda$CDM at a significance level >~ 5$\sigma$ with an individual MF measurement. Therefore, the MF of large scale structure is potentially a powerful probe of gravity, and its application to real data deserves active explorations.

D.S. Akerib, S. Alsum, C. Aquino, H.M. Araújo, X. Bai, A.J. Bailey, J. Balajthy, P. Beltrame, E.P. Bernard, A. Bernstein, T.P. Biesiadzinski, E.M. Boulton, P. Brás, D. Byram, S.B. Cahn, M.C. Carmona-Benitez, C. Chan, A.A. Chiller, C. Chiller, A. Currie, J.E. Cutter, T.J.R. Davison, A. Dobi, J.E.Y. Dobson, E. Druszkiewicz, B.N. Edwards, C.H. Faham, S.R. Fallon, S. Fiorucci, R.J. Gaitskell, V.M. Gehman, C. Ghag, K.R. Gibson, M.G.D. Gilchriese, C.R. Hall, M. Hanhardt, S.J. Haselschwardt, S.A. Hertel, D.P. Hogan, M. Horn, D.Q. Huang, C.M. Ignarra, R.G. Jacobsen, W. Ji, K. Kamdin, K. Kazkaz, D. Khaitan, R. Knoche, N.A. Larsen, C. Lee, B.G. Lenardo, K.T. Lesko, A. Lindote, M.I. Lopes, A. Manalaysay, R.L. Mannino, M.F. Marzioni, D.N. McKinsey, D.M. Mei, J. Mock, M. Moongweluwan, J.A. Morad, et al. (39 additional authors not shown)

The first searches for axions and axion-like particles with the Large Underground Xenon (LUX) experiment are presented. Under the assumption of an axio-electric interaction in xenon, the coupling constant between axions and electrons, gAe is tested, using data collected in 2013 with an exposure totalling 95 live-days $\times$ 118 kg. A double-sided, profile likelihood ratio statistic test excludes gAe larger than 3.5 $\times$ 10$^{-12}$ (90% C.L.) for solar axions. Assuming the DFSZ theoretical description, the upper limit in coupling corresponds to an upper limit on axion mass of 0.12 eV/c$^{2}$, while for the KSVZ description masses above 36.6 eV/c$^{2}$ are excluded. For galactic axion-like particles, values of gAe larger than 4.2 $\times$ 10$^{-13}$ are excluded for particle masses in the range 1-16 keV/c$^{2}$. These are the most stringent constraints to date for these interactions.

Federico Nati, Mark J. Devlin, Martina Gerbino, Bradley R. Johnson, Brian Keating, Luca Pagano, Grant Teply

We describe a novel method to measure the absolute orientation of the polarization plane of the CMB with arcsecond accuracy, enabling unprecedented measurements for cosmology and fundamental physics. Existing and planned CMB polarization instruments looking for primordial B-mode signals need an independent, experimental method for systematics control on the absolute polarization orientation. The lack of such a method limits the accuracy of the detection of inflationary gravitational waves, the constraining power on the neutrino sector through measurements of gravitational lensing of the CMB, the possibility of detecting Cosmic Birefringence, and the ability to measure primordial magnetic fields. Sky signals used for calibration and direct measurements of the detector orientation cannot provide an accuracy better than 1 deg. Self-calibration methods provide better accuracy, but may be affected by foreground signals and rely heavily on model assumptions. The POLarization Orientation CALibrator for Cosmology, POLOCALC, will dramatically improve instrumental accuracy by means of an artificial calibration source flying on balloons and aerial drones. A balloon-borne calibrator will provide far-field source for larger telescopes, while a drone will be used for tests and smaller polarimeters. POLOCALC will also allow a unique method to measure the telescopes' polarized beam. It will use microwave emitters between 40 and 150 GHz coupled to precise polarizing filters. The orientation of the source polarization plane will be registered to sky coordinates by star cameras and gyroscopes with arcsecond accuracy. This project can become a rung in the calibration ladder for the field: any existing or future CMB polarization experiment observing our polarization calibrator will enable measurements of the polarization angle for each detector with respect to absolute sky coordinates.

Paul H. Frampton, Holger B. Nielsen

It is said that there are no accidents or coincidences in physics. Within the minimal standard model combined with general relativity we point out that there are three exceptionally-long lifetimes which are consistent with being equal, and hence that there are two unexplained coincidences.