Heterotic string model building with monad bundles and reinforcement learning
Fortschritte der Physik Wiley 70:2-3 (2022) 2100186
Abstract:
We use reinforcement learning as a means of constructing string compactifications with prescribed properties. Specifically, we study heterotic (Formula presented.) GUT models on Calabi-Yau three-folds with monad bundles, in search of phenomenologically promising examples. Due to the vast number of bundles and the sparseness of viable choices, methods based on systematic scanning are not suitable for this class of models. By focusing on two specific manifolds with Picard numbers two and three, we show that reinforcement learning can be used successfully to explore monad bundles. Training can be accomplished with minimal computing resources and leads to highly efficient policy networks. They produce phenomenologically promising states for nearly 100% of episodes and within a small number of steps. In this way, hundreds of new candidate standard models are found.Non-standard neutrino interactions in IceCube
Sissa Medialab Srl (2022) 245
Strong constraints on neutrino nonstandard interactions from TeV-scale $\nu_\mu$ disappearance at IceCube
(2022)
Anomalous couplings in associated VH production with Higgs boson decay to massive b quarks at NNLO in QCD
Physical Review D American Physical Society (APS) 105:1 (2022) 014023
A Challenge to the Standard Cosmological Model
To appear in APJ Letters, 2022
Abstract:
We present the first joint analysis of catalogs of radio galaxies and quasars to determine if their sky distribution is consistent with the standard $\Lambda$CDM model of cosmology. This model is based on the cosmological principle, which asserts that the universe is statistically isotropic and homogeneous on large scales, so the observed dipole anisotropy in the cosmic microwave background (CMB) must be attributed to our local peculiar motion. We test the null hypothesis that there is a dipole anisotropy in the sky distribution of radio galaxies and quasars consistent with the motion inferred from the CMB, as is expected for cosmologically distant sources. Our two samples, constructed respectively from the NRAO VLA Sky Survey and the Wide-field Infrared Survey Explorer, are systematically independent and have no shared objects. Using a completely general statistic that accounts for correlation between the found dipole amplitude and its directional offset from the CMB dipole, the null hypothesis is independently rejected by the radio galaxy and quasar samples with $p$-value of $8.9\times10^{-3}$ and $1.2\times10^{-5}$, respectively, corresponding to $2.6\sigma$ and $4.4\sigma$ significance. The joint significance, using sample size-weighted $Z$-scores, is $5.1\sigma$. We show that the radio galaxy and quasar dipoles are consistent with each other and find no evidence for any frequency dependence of the amplitude. The consistency of the two dipoles improves if we boost to the CMB frame assuming its dipole to be fully kinematic, suggesting that cosmologically distant radio galaxies and quasars may have an intrinsic anisotropy in this frame.