Fundamental constants and tests of theory in Rydberg states of hydrogenlike ionsThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at University of Windsor, Windsor, Ontario, Canada on 21–26 July 2008.

2009 ◽  
Vol 87 (7) ◽  
pp. 757-762 ◽  
Author(s):  
Ulrich D. Jentschura ◽  
Peter J. Mohr ◽  
Joseph N. Tan ◽  
Benedikt J. Wundt
Keyword(s):  
Quantum Electrodynamic ◽  
Rydberg States ◽  
Test Theory ◽  
Fundamental Constants ◽  
Atomic Systems ◽  
Rydberg Constant ◽  
Theoretical Predictions ◽  
Size Correction ◽  
Precision Frequency ◽  
Theoretical Results

A comparison of precision frequency measurements to quantum electrodynamic (QED) theoretical predictions can be used to test theory and to obtain information regarding fundamental constants. We find that for Rydberg states, theoretical uncertainties due to the problematic nuclear size correction are very small. With the help of QED calculations, the largest remaining source of uncertainty can be eliminated. Theoretical predictions, taking advantage of the latest theoretical results, in combination with planned experiments, can lead to an improved value for the Rydberg constant.

The Convergence of the H-P Version of the Finite Element Method with Quasi-Uniform Meshes for Three Dimensional Poisson Problems with Edge Singularity

2014 ◽  
Vol 644-650 ◽  
pp. 1551-1555
Author(s):  
Jian Ming Zhang ◽  
Yong He
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Weighted Sobolev Spaces ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Smooth Functions ◽  
Edge Singularity ◽  
Theoretical Predictions ◽  
Theoretical Results ◽  
Element Method

This paper is concerned with the convergence of the h-p version of the finite element method for three dimensional Poisson problems with edge singularity on quasi-uniform meshes. First, we present the theoretical results for the convergence of the h-p version of the finite element method with quasi-uniform meshes for elliptic problems on polyhedral domains on smooth functions in the framework of Jacobi-weighted Sobolev spaces. Second, we investigate and analyze numerical results for three dimensional Poission problems with edge singularity. Finally, we verified the theoretical predictions by the numerical computation.

New Measurement of the Rydberg Constant by Two-Photon Spectroscopy of Hydrogen Rydberg States

1989 ◽  
Vol 62 (6) ◽  
pp. 621-624 ◽  
Author(s):  
F. Biraben ◽  
J. C. Garreau ◽  
L. Julien ◽  
M. Allegrini
Keyword(s):  
Rydberg States ◽  
Two Photon ◽  
Rydberg Constant

Experimental and theoretical fatigue-crack propagation lives of variously notched plates

1974 ◽  
Vol 9 (2) ◽  
pp. 61-66 ◽  
Author(s):  
R A Smith ◽  
K Jerram ◽  
K J Miller
Keyword(s):  
Fatigue Life ◽  
Crack Propagation ◽  
Finite Element Analyses ◽  
Intensity Factors ◽  
Complex Profile ◽  
Propagation Law ◽  
Theoretical Predictions ◽  
Life Predictions ◽  
Theoretical Results

The fatigue lives of variously notched plates have been determined theoretically and experimentally. Theoretical predictions of fatigue lives involved the determination of stress-intensity factors from finite-element analyses. By invoking a crack propagation law, fatigue-life predictions were made for four specimens. Fatigue experiments were conducted on four notched plates subjected to end load plus bending. Comparison with theoretical results shows that the experimental lives were greater by factors of 1.30 to 1.54. These results are most satisfactory since (1) a safe prediction of fatigue life has been made for a complex profile subjected to non-simple loading conditions, and (2) a theoretical elastic analysis has sufficed for a situation involving plastic strains.

Possible gapless chiral phase in a frustrated S = 1 1D anti-ferromagnet, CaV2O4

2001 ◽  
Vol 79 (11-12) ◽  
pp. 1551-1555 ◽  
Author(s):  
H Kikuchi ◽  
M Chiba ◽  
T Kubo
Keyword(s):  
Magnetic Susceptibility ◽  
Spin Chain ◽  
Chiral Phase ◽  
Spin Gap ◽  
Spin Freezing ◽  
Model Substance ◽  
Theoretical Predictions ◽  
Ferromagnetic Interactions ◽  
Theoretical Results ◽  
Broad Region

We have measured magnetic susceptibility and 51V NMR of CaV2O4, a model substance for a frustrated S = 1 spin chain with competing first- and second-neighbor anti-ferromagnetic interactions. Both the low-temperature magnetic susceptibility and the NMR Knight shift did not go down to zero as the temperature was lowered, suggesting that a spin gap is not present in CaV2O4. The absence of a spin gap gives us a clear contrast to the case of the nonfrustrated spin chains, which should have the Haldane gap. Recently published theoretical results for S = 1 XY or XXZ spin chain indicate that the gapless chiral phase could appear in a relatively broad region. Experimental results are discussed in terms of these theoretical predictions. A spin-freezing anomaly was observed at 20 K, reflecting the spin-frustrating nature of the system. PACS Nos.: 75.30, 75.50

Rydberg States of Atomic Systems

2012 ◽  
pp. 57-104
Author(s):  
Boris Mikhailovich Karnakov ◽  
Vladimir Pavlovich Krainov
Keyword(s):  
Rydberg States ◽  
Atomic Systems

Dynamic polarizabilities and Rydberg states of open shell atomic systems

1988 ◽  
Vol 74 (6) ◽  
pp. 431-444 ◽  
Author(s):  
P. K. Mukherjee ◽  
K. Ohtsuki ◽  
K. Ohno
Keyword(s):  
Rydberg States ◽  
Open Shell ◽  
Atomic Systems ◽  
Dynamic Polarizabilities

scholarly journals VLT and E-ELT spectrographs & fundamental-constants

2009 ◽  
Vol 5 (H15) ◽  
pp. 326-326
Author(s):  
Paolo Molaro
Keyword(s):  
Fine Structure ◽  
Equivalence Principle ◽  
Structure Constant ◽  
Rate Of Change ◽  
Fine Structure Constant ◽  
Doppler Velocity ◽  
Fundamental Constants ◽  
Velocity Shift ◽  
Theoretical Predictions

The fundamental dimensionless physical constants cannot be predicted by theory but can only be measured experimentally. And so it is of their possible variation where there are several theoretical predictions but unfortunately with little theoretical guidance on the expected rate of change. The role of fundamental constants in the representation of nature as well as the implications of their variability for the Equivalence Principle and cosmology have been highlighted in many contributions at this conference (cfr K. Olive and J.P Uzan, these proceedings). Measuring the variability of the fine structure constant α or the electron-to-proton ratio μ by means of absorption lines implies the measurement of a tiny variation of the position of one or a few lines with regard to other lines which are taken as reference. For the fine structure constant the relation between its change and the doppler velocity shift is:

Thermal Behavior and Friction in Journal Bearings

1970 ◽  
Vol 92 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Al. Nica
Keyword(s):  
Experimental Data ◽  
Thermal Behavior ◽  
Heat Dissipation ◽  
Journal Bearings ◽  
Friction Torque ◽  
Operating Characteristics ◽  
Lubricant Flow ◽  
Theoretical Predictions ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with friction and the field of temperature in the lubricant film of journal bearings. Theoretical results regarding the thermal behavior are checked with experimental data and good agreement is found. Emphasis is put on the variation of temperature and lubricant flow with the operating characteristics of the bearing and it is seen that theoretical predictions for minima of friction torque are backed by temperature measurements. Further on, the friction torque and the mechanism of heat dissipation in bearings are dealt with, in order to verify the assumptions used in the calculation schemes. The means of efficiently cooling the bearing are also discussed, as well as the part played by the divergent zone in this process.

scholarly journals Primordial nucleosynthesis with varying fundamental constants

2020 ◽  
Vol 633 ◽  
pp. L11 ◽  
Author(s):  
M. T. Clara ◽  
C. J. A. P. Martins
Keyword(s):  
Standard Model ◽  
Broad Class ◽  
Statistical Significance ◽  
Structure Constant ◽  
Big Bang ◽  
Fine Structure Constant ◽  
Fundamental Constants ◽  
Primordial Nucleosynthesis ◽  
The Standard Model ◽  
Theoretical Predictions

Primordial nucleosynthesis is an observational cornerstone of the Hot Big Bang model and a sensitive probe of physics beyond the standard model. Its success has been limited by the so-called lithium problem, for which many solutions have been proposed. We report on a self-consistent perturbative analysis of the effects of variations in nature’s fundamental constants, which are unavoidable in most extensions of the standard model, on primordial nucleosynthesis, focusing on a broad class of Grand Unified Theory models. A statistical comparison between theoretical predictions and observational measurements of 4He, D, 3He and, 7Li consistently yields a preferred value of the fine-structure constant α at the nucleosynthesis epoch that is larger than the current laboratory one. The level of statistical significance and the preferred extent of variation depend on model assumptions but the former can be more than four standard deviations, while the latter is always compatible with constraints at lower redshifts. If lithium is not included in the analysis, the preference for a variation of α is not statistically significant. The abundance of 3He is relatively insensitive to such variations. Our analysis highlights a viable and physically motivated solution to the lithium problem, which warrants further study.

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