Potential advantages of chiral molecules for a sensitive search for parity violating cosmic fields are highlighted. Such fields are invoked in different models for cold dark matter or in the Lorentz-invariance violating standard model extensions and thus are signatures of physics beyond the standard model. The sensitivity of a 20-year-old experiment with the molecule CHBrClF to pseudovector cosmic fields as characterized by the parameter |b_{0}^{e}| is estimated to be O(10^{-12} GeV) employing ab initio calculations. This allows us to project the sensitivity of future experiments with favorable choices of chiral heavy-elemental molecular probes to be O(10^{-17} GeV), which will be an improvement of the present best limits by at least two orders of magnitude.
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http://dx.doi.org/10.1103/PhysRevLett.125.123004 | DOI Listing |
Sci Rep
January 2025
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Nanoscale Fourier transform infrared (Nano-FTIR) imaging and spectroscopy correlated with photoluminescence measurements of lunar Apollo samples with different surface radiation exposure histories reveal distinct physical and chemical differences associated with space weathering effects. Analysis of two sample fragments: an ilmenite basalt (12016) and an impact melt breccia (15445) show evidence of intrinsic or delivered Nd and an amorphous silica glass component on exterior surfaces, whereas intrinsic Cr and/or trapped electron states are limited to interior surfaces. Spatially localized 1050 cm/935 cm band ratios in Nano-FTIR hyperspectral maps may further reflect impact-induced shock nanostructures, while shifts in silicate band positions indicate accumulated radiation damage at the nanoscale from prolonged space weathering due to micrometeorites, solar wind, energetic x-rays and cosmic ray bombardment.
View Article and Find Full Text PDFBiomed Phys Eng Express
December 2024
Biomechatronics Laboratory Mechatronics Department, University of Sao Paulo, Av Prof Mello Moraes 2331, Cidade Universitaria, 05508-030 Sao Paulo-SP, Sao Paulo, 05508-900, BRAZIL.
Characterization of the electroencephalography (EEG) signals related to motor activity, such as alpha- and beta-band motor event-related desynchronizations (ERDs), is essential for Brain Computer Interface (BCI) development. Determining the best electrode combination to detect the ERD is crucial for the success of the BCI. Considering that the EEG signals are bipolar, this involves the choice of the main and reference electrodes.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, Rio de Janeiro 22451-900, RJ, Brazil.
The effects of cosmic-ray bombardment of chiral molecules in the interstellar medium are simulated in the laboratory by performing radiolysis experiments of pure α-pinene ices at four different temperatures. The identification and significance of α-pinene have not been fully understood because of the insufficient amount of spectral information of these compounds at low temperatures. A comparison of the temperature dependence of the mid-infrared spectra of pure α-pinene ices before and after irradiation its irradiation by 61.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, 85748 Garching, Germany.
We present optimal Bayesian field-level cosmological constraints from nonlinear tracers of cosmic large-scale structure, specifically the amplitude σ_{8} of linear matter fluctuations inferred from rest-frame simulated dark matter halos in a comoving volume of 8 (h^{-1} Gpc)^{3}. Our constraint on σ_{8} is entirely due to nonlinear information, and obtained by explicitly sampling the initial conditions along with tracer bias and noise parameters via a Lagrangian effective field theory-based forward model, leftfield. The comparison with a simulation-based inference of the power spectrum and bispectrum-likewise using the leftfield forward model-shows that, when including precisely the same modes of the same data up to k_{max}=0.
View Article and Find Full Text PDFJ Geophys Res Space Phys
December 2024
MLT Haystack Observatory Westford MA USA.
We use the TIEGCM-NG nudged by MAGIC gravity waves to study the impacts of a severe thunderstorm system, with a hundred tornado touchdowns, on the ionospheric and thermospheric disturbances. The generated waves induce a distinct concentric ring pattern on GNSS TIDs with horizontal scales of 150-400 km and phase speeds of 150-300 m/s, which is well simulated by the model. The waves show substantial vertical evolution in period, initially dominated by 0.
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