321 research outputs found
Modulation of Spinal Neural Circuits Induced by Corticospinal Descending and Peripheral Afferent Inputs
皮質脊髄路からの下行性入力および抹消からの感覚入力によって引き起こされる脊髄神経回路の調節
広島大学(Hiroshima University)博士(学術)Doctor of Philosophydoctora
On spin optics for gravitational waves lensed by a rotating object
We study gravitational lensing of gravitational waves taking into account the
spin of a graviton coupled with a dragged spacetime made by a rotating object.
We decompose the phase of gravitational waves into helicity-dependent and
independent components with spin optics, analyzing waves whose wavelengths are
shorter than the curvature radius of a lens object. We analytically confirm
that the trajectory of gravitational waves splits depending on the helicity,
generating additional time delay and elliptical polarization onto the
helicity-independent part. We exemplify monotonic gravitational waves lensed by
a Kerr black hole and derive the analytical expressions of corrections in phase
and magnification. The corrections are enhanced for longer wavelengths,
potentially providing a novel probe of rotational properties of lens objects in
low-frequency gravitational-wave observations in the future.Comment: 14 pages, 6 figure
Nonlinear behavior and mode coupling in spin transfer nano-oscillators
By investigating thoroughly the tunable behavior of coupled modes, we
highlight how it provides new means to handle the properties of spin transfer
nano-oscillators. We first demonstrate that the main features of the microwave
signal associated with coupled vortex dynamics i.e. frequency, spectral
coherence, critical current, mode localization, depends drastically on the
relative vortex core polarities. Secondly we report a large reduction of the
nonlinear linewidth broadening obtained by changing the effective damping
through the control of the core configuration. Such a level of control on the
nonlinear behavior reinforces our choice to exploit the microwave properties of
collective modes for applications of spintronic devices in novel generation of
integrated telecommunication devices
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