Obtaining Precision Constraints on Modified Gravity with Helioseismology.

We propose helioseismology as a new, precision probe of fifth forces at astrophysical scales, and apply it on the most general scalar-tensor theories for dark energy, known as degenerate higher-order scalar-tensor theories. We explain how the effect of the fifth force on the solar interior leaves an observable imprint on the acoustic oscillations, and under certain assumptions we numerically compute the nonradial pulsation eigenfrequencies within modified gravity. We illustrate its constraining power by showing that helioseismic observations have the potential to improve constraints on the strength of the fifth force by more than 2 orders of magnitude, as -1.8×10^{-3}≤Y≤1.2×10^{-3} (at 2σ). This in turn would suggest constraints of similar order for the theory's free functions around a cosmological background (α_{H}, ß_{1}).

Neutrino spectroscopy can probe the dark matter content in the Sun.

After being gravitationally captured, low-mass cold dark-matter particles (mass range from 5 to ~50 × 10(9) electron volts) are thought to drift to the center of the Sun and affect its internal structure. Solar neutrinos provide a way to probe the physical processes occurring in the Sun's core. Solar neutrino spectroscopy, in particular, is expected to measure the neutrino fluxes produced in nuclear reactions in the Sun. Here, we show how the presence of dark-matter particles inside the Sun will produce unique neutrino flux distributions in (7)Be-ν and (8)B-ν, as well as (13)N-ν, (15)O-ν, and (17)F-ν.

Solar neutrinos: probing the quasi-isothermal solar core produced by supersymmetric dark matter particles.

SNO measurements strongly constrain the central temperature of the Sun, to within a precision of much less than 1%. This result can be used to probe the parameter space of supersymmetric dark matter. In this first analysis we find a lower limit for the weakly interacting massive particle (WIMP) mass of 60 GeV. Furthermore, in the event that WIMPs create a quasi-isothermal core, they will produce a peculiar distribution of the solar neutrino fluxes measured on Earth. Typically, a WIMP with a mass of 100 GeV and annihilation cross section of 10(-34) cm(3)/sec will decrease the neutrino predictions, by up to 4% for the Cl, by 3% for the heavy water, and by 1% for the Ga detectors.