Quantum field theory predicts a nonlinear response of the vacuum to strong electromagnetic fields of macroscopic extent.This fundamental tenet has remained experimentally challenging and is yet to be tested in the lab...Quantum field theory predicts a nonlinear response of the vacuum to strong electromagnetic fields of macroscopic extent.This fundamental tenet has remained experimentally challenging and is yet to be tested in the laboratory.A particularly distinct signature of the resulting optical activity of the quantum vacuum is vacuum birefringence.This offers an excellent opportunity for a precision test of nonlinear quantum electrodynamics in an uncharted parameter regime.Recently,the operation of the high-intensity Relativistic Laser at the X-ray Free Electron Laser provided by the Helmholtz International Beamline for Extreme Fields has been inaugurated at the High Energy Density scientific instrument of the European X-ray Free Electron Laser.We make the case that this worldwide unique combination of an X-ray free-electron laser and an ultra-intense near-infrared laser together with recent advances in high-precision X-ray polarimetry,refinements of prospective discovery scenarios and progress in their accurate theoretical modelling have set the stage for performing an actual discovery experiment of quantum vacuum nonlinearity.展开更多
t Six new species of Diaporthe,D.beilharziae on Indigofera australis,D.fraxini-angustifoliae on Fraxinus angustifolia subsp.oxycarpa,D.litchicola on Litchi chinensis,D.nothofagi on Nothofagus cunninghamii,D.pascoei on...t Six new species of Diaporthe,D.beilharziae on Indigofera australis,D.fraxini-angustifoliae on Fraxinus angustifolia subsp.oxycarpa,D.litchicola on Litchi chinensis,D.nothofagi on Nothofagus cunninghamii,D.pascoei on Persea americana and D.salicicola on Salix purpurea from Australia are described and illustrated based on morphological characteristics and molecular analyses.Three of the new species no longer produced sporulating structures in culture and two of these were morphologically described from voucher specimens.Phylogenetic relationships of the new species with other Diaporthe species are revealed by DNA sequence analyses based on the internal transcribed spacer(ITS)region,and partial regions of theβtubulin(BT)and translation elongation factor 1-alpha(TEF).展开更多
基金funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Grants Nos.392856280,416611371,416607684,416702141 and 416708866 within the Research Unit FOR2783/2 and Project-ID 278162697–SFB 1242.
文摘Quantum field theory predicts a nonlinear response of the vacuum to strong electromagnetic fields of macroscopic extent.This fundamental tenet has remained experimentally challenging and is yet to be tested in the laboratory.A particularly distinct signature of the resulting optical activity of the quantum vacuum is vacuum birefringence.This offers an excellent opportunity for a precision test of nonlinear quantum electrodynamics in an uncharted parameter regime.Recently,the operation of the high-intensity Relativistic Laser at the X-ray Free Electron Laser provided by the Helmholtz International Beamline for Extreme Fields has been inaugurated at the High Energy Density scientific instrument of the European X-ray Free Electron Laser.We make the case that this worldwide unique combination of an X-ray free-electron laser and an ultra-intense near-infrared laser together with recent advances in high-precision X-ray polarimetry,refinements of prospective discovery scenarios and progress in their accurate theoretical modelling have set the stage for performing an actual discovery experiment of quantum vacuum nonlinearity.
文摘t Six new species of Diaporthe,D.beilharziae on Indigofera australis,D.fraxini-angustifoliae on Fraxinus angustifolia subsp.oxycarpa,D.litchicola on Litchi chinensis,D.nothofagi on Nothofagus cunninghamii,D.pascoei on Persea americana and D.salicicola on Salix purpurea from Australia are described and illustrated based on morphological characteristics and molecular analyses.Three of the new species no longer produced sporulating structures in culture and two of these were morphologically described from voucher specimens.Phylogenetic relationships of the new species with other Diaporthe species are revealed by DNA sequence analyses based on the internal transcribed spacer(ITS)region,and partial regions of theβtubulin(BT)and translation elongation factor 1-alpha(TEF).
