scholarly journals Eccentric-orbit extreme-mass-ratio-inspiral radiation: Analytic forms of leading-logarithm and subleading-logarithm flux terms at high PN orders

2019 ◽  
Vol 100 (10) ◽  
Author(s):  
Christopher Munna ◽  
Charles R. Evans
Keyword(s):  
Mass Ratio ◽  
Eccentric Orbit ◽  
Leading Logarithm

scholarly journals On spin asymmetry in muon and tau decays

2018 ◽  
Vol 33 (32) ◽  
pp. 1850191
Author(s):  
A. B. Arbuzov ◽  
T. V. Kopylova ◽  
I. K. Sklyarov
Keyword(s):  
Charged Lepton ◽  
Spin Asymmetry ◽  
Second Order ◽  
Tau Leptons ◽  
Mass Ratio ◽  
Fermi Model ◽  
Tau Decays ◽  
Standard Formula ◽  
Leading Logarithm ◽  
Michel Parameters

The angular asymmetry in decays of polarized muons and tau leptons is discussed. Both the standard [Formula: see text] Fermi model and the general parametrization via Michel parameters are considered. Numerical importance of contributions suppressed by charged lepton mass ratio is underlined. Contribution of the second order QED correction is estimated in the leading logarithm approximation.

A Study of the Orbital and Intrinsic Variability of the Double-Lined Spectroscopic Binary β Centauri

2002 ◽  
Vol 185 ◽  
pp. 86-87
Author(s):  
M. Ausseloos ◽  
C. Aerts ◽  
K. Uytterhoeven
Keyword(s):  
High Resolution ◽  
Orbital Motion ◽  
High Signal ◽  
Mass Ratio ◽  
Eccentric Orbit ◽  
Intrinsic Variability ◽  
Signal To Noise ◽  
Orbital Parameters ◽  
Spectroscopic Binary ◽  
First Time

AbstractWe introduce our observational study of the orbital motion of β Cen. Using 463 high signal-to-noise, high-resolution spectra obtained over a timespan of 12 years it is shown that the radial velocity of β Cen varies with an orbital period of 357.0 days. We derive for the first time the orbital parameters of β Cen and find a very eccentric orbit (e = 0.81) and similar component masses with a mass ratio M1/M2 = 1.02. Both the primary and the secondary exhibit periodic line-profile variations.

scholarly journals Polar planets around highly eccentric binaries are the most stable

2020 ◽  
Vol 494 (4) ◽  
pp. 4645-4655
Author(s):  
Cheng Chen ◽  
Stephen H Lubow ◽  
Rebecca G Martin
Keyword(s):  
Semimajor Axis ◽  
Orbital Stability ◽  
Equal Mass ◽  
Escape Time ◽  
Mass Ratio ◽  
Eccentric Orbit ◽  
Polar Orbit ◽  
Formation And Evolution ◽  
Binary Orbit ◽  
The Stability

ABSTRACT We study the orbital stability of a non-zero mass, close-in circular orbit planet around an eccentric orbit binary for various initial values of the binary eccentricity, binary mass fraction, planet mass, planet semimajor axis, and planet inclination by means of numerical simulations that cover 5 × 104 binary orbits. For small binary eccentricity, the stable orbits that extend closest to the binary (most stable orbits) are nearly retrograde and circulating. For high binary eccentricity, the most stable orbits are highly inclined and librate near the so-called generalized polar orbit which is a stationary orbit that is fixed in the frame of the binary orbit. For more extreme mass ratio binaries, there is a greater variation in the size of the stability region (defined by initial orbital radius and inclination) with planet mass and initial inclination, especially for low binary eccentricity. For low binary eccentricity, inclined planet orbits may be unstable even at large orbital radii (separation ${\gt}5 \, a_{\rm b}$). The escape time for an unstable planet is generally shorter around an equal mass binary compared with an unequal mass binary. Our results have implications for circumbinary planet formation and evolution and will be helpful for understanding future circumbinary planet observations.

scholarly journals Three-loop radiative-recoil corrections to hyperfine splitting in muonium

2005 ◽  
Vol 83 (4) ◽  
pp. 363-373 ◽  
Author(s):  
Michael I Eides ◽  
Howard Grotch ◽  
Valery A Shelyuto
Keyword(s):  
Experimental Data ◽  
Hyperfine Splitting ◽  
Theoretical Uncertainty ◽  
Invariant Sets ◽  
Mass Ratio ◽  
Gauge Invariant ◽  
Muon Mass ◽  
Long Time ◽  
Muonium Hyperfine ◽  
Leading Logarithm

We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium. These corrections are enhanced by the large logarithm of the electron–muon mass ratio. The leading logarithm-cubed and logarithm-squared contributions were obtained a long time ago. We calculate the single-logarithmic and nonlogarithmic contributions of order α3(m/M)EF generated by gauge invariant sets of diagrams with one- and two-loop polarization insertions in diagrams with two exchanged photons and radiative photons, and by diagrams with one-loop radiative photon insertions both in the electron and muon lines. The results of this paper constitute a next step in the implementation of the program of reduction of the theoretical uncertainty of hyperfine splitting below 10 Hz. They improve the theory of hyperfine splitting, and affect the value of the electron–muon mass ratio extracted from experimental data on the muonium hyperfine splitting.PACS Nos.: 12.20.Ds, 31.30.Jv, 32.10.Fn, 36.10.Dr

Effectiveness of Location and Number of Multiple Tuned Mass Damper for Seismic Structures

2020 ◽  
Vol 9 (6) ◽  
pp. 780-783
Keyword(s):  
Seismic Response ◽  
Software Tool ◽  
Tuned Mass Damper ◽  
Structure Study ◽  
Structural Performance ◽  
Mass Ratio ◽  
Tuned Mass Dampers ◽  
Maximum Reduction ◽  
Mass Damper ◽  
Earthquake Data

Tuned mass dampers (TMD) are one of the most reliable devices to control the vibration of the structure. The optimum mass ratio required for a single tuned mass damper (STMD) is evaluated corresponding to the fundamental natural frequency of the structure. The effect of STMD and Multiple tuned mass dampers (MTMD) on a G+20 storey structure are studied to demonstrate the damper’s effectiveness in seismic application. The location and number of tuned mass dampers are studied to give best structural performance in maximum reduction of seismic response for El Centro earthquake data. The analysis results from SAP 2000 software tool shows damper weighing 2.5% of the total weight of the structure effectively reduce the response of the structure. Study shows that introduction of 4-MTMD at top storey can effectively reduce the response by 10% more in comparison to single tuned mass damper. The use of MTMD of same mass ratio that of STMD is more effective in seismic response.

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