The Experts below are selected from a list of 41244 Experts worldwide ranked by ideXlab platform
Yeinzon Rodriguez - One of the best experts on this subject based on the ideXlab platform.
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statistical anisotropy of the curvature perturbation from vector field perturbations
Journal of Cosmology and Astroparticle Physics, 2009Co-Authors: Konstantinos Dimopoulos, Mindaugas Karciauskas, David H Lyth, Yeinzon RodriguezAbstract:The δN formula for the primordial curvature perturbation ζ is extended to include vector as well as scalar fields. Formulas for the tree-level contributions to the spectrum and bispectrum of ζ are given, exhibiting statistical anisotropy. The one-loop contribution to the spectrum of ζ is also worked out. We then consider the generation of vector field perturbations from the vacuum, including the Longitudinal Component that will be present if there is no gauge invariance. Finally, the δN formula is applied to the vector curvaton and vector inflation models with the tensor perturbation also evaluated in the latter case.
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statistical anisotropy of the curvature perturbation from vector field perturbations
arXiv: Astrophysics, 2008Co-Authors: Konstantinos Dimopoulos, Mindaugas Karciauskas, David H Lyth, Yeinzon RodriguezAbstract:The \delta N formula for the primordial curvature perturbation \zeta is extended to include vector as well as scalar fields. Formulas for the tree-level contributions to the spectrum and bispectrum of \zeta are given, exhibiting statistical anisotropy. The one-loop contribution to the spectrum of \zeta is also worked out. We then consider the generation of vector field perturbations from the vacuum, including the Longitudinal Component that will be present if there is no gauge invariance. Finally, the \delta N formula is applied to the vector curvaton and vector inflation models with the tensor perturbation also evaluated in the latter case.
Peter G. Kazansky - One of the best experts on this subject based on the ideXlab platform.
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laser material processing with tightly focused cylindrical vector beams
Applied Physics Letters, 2016Co-Authors: Rokas Drevinskas, Yuri Svirko, Martynas Beresna, Mindaugas Gecevicius, Andrey G. Kazanskii, Jingyu Zhang, Peter G. KazanskyAbstract:We demonstrate a comprehensive modification study of silica glass, crystalline silicon, and amorphous silicon film, irradiated by tightly focused cylindrical vector beams with azimuthal and radial polarizations. The evidence of the Longitudinal field associated with radial polarization is revealed by second harmonic generation in z-cut lithium niobate crystal. Despite the lower threshold of ring-shaped modification of silicon materials, the modification in the center of single pulse radially polarized beam is not observed. The phenomenon is interpreted in terms of the enhanced reflection of Longitudinal Component at the interface with high-index contrast, demonstrating that the Longitudinal Component is inefficient for the flat surface modification. Enhanced interaction of the Longitudinal light field with silicon nanopillar structures produced by the first pulse of double-pulse irradiation is also demonstrated.
Yuri Svirko - One of the best experts on this subject based on the ideXlab platform.
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laser material processing with tightly focused cylindrical vector beams
Applied Physics Letters, 2016Co-Authors: Rokas Drevinskas, Yuri Svirko, Martynas Beresna, Mindaugas Gecevicius, Andrey G. Kazanskii, Jingyu Zhang, Peter G. KazanskyAbstract:We demonstrate a comprehensive modification study of silica glass, crystalline silicon, and amorphous silicon film, irradiated by tightly focused cylindrical vector beams with azimuthal and radial polarizations. The evidence of the Longitudinal field associated with radial polarization is revealed by second harmonic generation in z-cut lithium niobate crystal. Despite the lower threshold of ring-shaped modification of silicon materials, the modification in the center of single pulse radially polarized beam is not observed. The phenomenon is interpreted in terms of the enhanced reflection of Longitudinal Component at the interface with high-index contrast, demonstrating that the Longitudinal Component is inefficient for the flat surface modification. Enhanced interaction of the Longitudinal light field with silicon nanopillar structures produced by the first pulse of double-pulse irradiation is also demonstrated.
Alexander Shnirman - One of the best experts on this subject based on the ideXlab platform.
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quantitative evaluation of defect models in superconducting phase qubits
Applied Physics Letters, 2010Co-Authors: Jared H Cole, Clemens Muller, P Bushev, G J Grabovskij, J Lisenfeld, A Lukashenko, A V Ustinov, Alexander ShnirmanAbstract:We use high-precision spectroscopy and detailed theoretical modeling to determine the form of the coupling between a superconducting phase qubit and a two-level defect. Fitting the experimental data with our theoretical model allows us to determine all relevant system parameters. We observe a strong qubit-defect coupling with a nearly vanishing Longitudinal Component. We quantitatively compare several existing theoretical models for the microscopic origin of two-level defects.
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quantitative evaluation of defect models in superconducting phase qubits
arXiv: Superconductivity, 2010Co-Authors: Jared H Cole, Clemens Muller, P Bushev, G J Grabovskij, J Lisenfeld, A Lukashenko, A V Ustinov, Alexander ShnirmanAbstract:We use high-precision spectroscopy and detailed theoretical modelling to determine the form of the coupling between a superconducting phase qubit and a two-level defect. Fitting the experimental data with our theoretical model allows us to determine all relevant system parameters. A strong qubit-defect coupling is observed, with a nearly vanishing Longitudinal Component. Using these estimates, we quantitatively compare several existing theoretical models for the microscopic origin of two-level defects.
Konstantinos Dimopoulos - One of the best experts on this subject based on the ideXlab platform.
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statistical anisotropy of the curvature perturbation from vector field perturbations
Journal of Cosmology and Astroparticle Physics, 2009Co-Authors: Konstantinos Dimopoulos, Mindaugas Karciauskas, David H Lyth, Yeinzon RodriguezAbstract:The δN formula for the primordial curvature perturbation ζ is extended to include vector as well as scalar fields. Formulas for the tree-level contributions to the spectrum and bispectrum of ζ are given, exhibiting statistical anisotropy. The one-loop contribution to the spectrum of ζ is also worked out. We then consider the generation of vector field perturbations from the vacuum, including the Longitudinal Component that will be present if there is no gauge invariance. Finally, the δN formula is applied to the vector curvaton and vector inflation models with the tensor perturbation also evaluated in the latter case.
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statistical anisotropy of the curvature perturbation from vector field perturbations
arXiv: Astrophysics, 2008Co-Authors: Konstantinos Dimopoulos, Mindaugas Karciauskas, David H Lyth, Yeinzon RodriguezAbstract:The \delta N formula for the primordial curvature perturbation \zeta is extended to include vector as well as scalar fields. Formulas for the tree-level contributions to the spectrum and bispectrum of \zeta are given, exhibiting statistical anisotropy. The one-loop contribution to the spectrum of \zeta is also worked out. We then consider the generation of vector field perturbations from the vacuum, including the Longitudinal Component that will be present if there is no gauge invariance. Finally, the \delta N formula is applied to the vector curvaton and vector inflation models with the tensor perturbation also evaluated in the latter case.
