High-resolution imaging observations from the Hinode spacecraft in the Ca II H line are employed to study the dynamics of the chromosphere above a sunspot. We find that umbral flashes and other brightenings produced by the oscillation are extremely rich in fine structure, even beyond the resolving limit of our observations (0.22”). The umbra is tremendously dynamic, to the point that our time c...

Recently there has been a strong interest in cross-frequency coupling, the interaction between neuronal oscillations in different frequency bands. In particular, measures quantifying the coupling between the phase of slow oscillations and the amplitude of fast oscillations have been applied to a wide range of data recorded from animals and humans. Some of the measures applied to detect phase-am...

Helioseismology has revealed many details of solar differential rotation and also its time variation, known as torsional oscillations. So far there is no generally accepted theoretical explanation for torsional oscillations, even though a close relation to the solar activity cycle is evident. On the theoretical side non-kinematic dynamo models (including the Lorentz force feedback on differenti...

We take another look at “Just-So” solar neutrino oscillations and characterize them by the energy at which the distance-varying angle is π/2. The SuperKamiokande spectrum can be fit with an energy in the range of 9-12 MeV. In this case, the pp neutrinos are reduced to half the standard solar model prediction and Be neutrinos must make up a significant part of the gallium signal, in contrast to ...

Spectropolarimetric time series data of the primary spot of active region NOAA 9448 were obtained in the Si i 10827 Å line and the He i 10830 Å multiplet with the Tenerife Infrared Polarimeter. Throughout the time series the spectrograph slit was fixed over a region covering umbra, a light bridge, penumbra, and quiet sun. We present speeds of running penumbral waves in the chromosphere, their r...

The description of neutrino propagation through a fluctuating medium is summarized. Fluctuation-Dissipation-Theorem arguments relate microscopic fluctuations to thermodynamic quantities, allowing these to be very generally studied in astro-physical environments. Fluctuation-induced modifications to neutrino oscillations have been studied in detail within the Sun and within the envelope of super...