The past several years have seen the emergence of a standard cosmological model, in which small temperature differences in the cosmic microwave background (CMB) radiation on angular scales of the order of a degree are understood to arise from acoustic oscillations in the hot plasma of the early Universe, arising from primordial density fluctuations. Within the context of this model, recent measurements of the temperature fluctuations have led to profound conclusions about the origin, evolution and composition of the Universe. Using the measured temperature fluctuations, the theoretical framework predicts the level of polarization of the CMB with essentially no free parameters. Therefore, a measurement of the polarization is a critical test of the theory and thus of the validity of the cosmological parameters derived from the CMB measurements. Here we report the detection of polarization of the CMB with the Degree Angular Scale Interferometer (DASI). The polarization is deteced with high confidence, and its level and spatial distribution are in excellent agreement with the predictions of the standard theory.
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http://dx.doi.org/10.1038/nature01269 | DOI Listing |
Nanoscale
January 2025
Sorbonne Université, MONARIS, CNRS-UMR 8233, 4 Place Jussieu, F-75005 Paris, France.
Developing chiral plasmonic nanostructures represents a significant scientific challenge due to their multidisciplinary potential. Observations have revealed that the dichroic behavior of metal plasmons changes when chiral molecules are present in the system, offering promising applications in various fields such as nano-optics, asymmetric catalysis, polarization-sensitive photochemistry and molecular detection. In this study, we explored the synthesis of plasmonic gold nanoparticles and the role of cysteine in their chiroplasmonic properties.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Distinguishing whether a system supports alternate low-energy (locally stable) states-stable (true vacuum) versus metastable (false vacuum)-by direct observation can be difficult when the lifetime of the state is very long but otherwise unknown. Here we demonstrate, in a tractable model system, that there are physical phenomena on much shorter timescales that can diagnose the difference. Specifically, we study the time evolution of the magnetization following a quench in the tilted quantum Ising model, and show that its magnitude spectrum is an effective diagnostic.
View Article and Find Full Text PDFFront Sports Act Living
December 2024
Department of Sport Science, Human Performance Research Centre, University of Konstanz, Konstanz, Germany.
Background: The physical and mental demands of handball during training or competition often lead to fatigue which can impair performance. Many attempts have been made to assess the level of fatigue in athletes either by objective (neuromuscular performance) or subjective (questionnaires) measures, however, their interplay over short-, mid-, and long-term periods is currently unknown. Knowledge about both types of assessments is important as load management by coaches is traditionally based on direct adjustments following a training session, adjustments of content structure of training weeks between games, as well as adjustments of load management over the entire competitive season.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India.
Herein, we present a novel liquid crystal (LC)-based sensing platform utilizing microgel-stabilized Pickering LC droplets dispersed in water for simple and label-free detection of proteins in an aqueous environment. This could be achieved by tailoring the surface of 4-cyano-4'-pentylbiphenyl (5CB) LC droplets dispersed in aqueous medium through the interfacial adsorption of poly(-isopropylacrylamide) (PNIPAM) microgel particles, followed by the introduction of model surfactants, such as anionic sodium dodecyl sulfate and cationic dodecyltrimethylammonium bromide. These surfactant/microgel complex-coated LC droplets underwent a configurational transition from radial-to-bipolar under a polarized optical microscope, upon exposure to model proteins, namely bovine serum albumin and lysozyme.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics and Astronomy, University of Manchester, Manchester, UK.
Unconventional superconductivity, where electron pairing does not involve electron-phonon interactions, is often attributed to magnetic correlations in a material. Well known examples include high-T cuprates and uranium-based heavy fermion superconductors. Less explored are unconventional superconductors with strong spin-orbit coupling, where interactions between spin-polarised electrons and external magnetic field can result in multiple superconducting phases and field-induced transitions between them, a rare phenomenon in the superconducting state.
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