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The origin of highest energy cosmic rays remains unresolved. High-energy neutrinos may provide the clues to fundamental phenomena such as the origin of cosmic rays or dark matter in the Universe. The IceCube Neutrino Observatory, a km scale neutrino detector, has come into full operation in 2011. At the highest energy levels, prototypes of a new experiment, the Askaryan Radio Array, have been deployed and are being tested. We report on the status, first results and prospects of the experimental neutrino searches under way and planned at the South Pole.

We present recent results from the Antarctic Muon And Neutrino Detector Array (AMANDA), located at the South Pole in Antarctica. AMANDA-II, commissioned in 2000, is a multipurpose high energy neutrino telescope with a broad physics and astrophysics scope. We summarize the results from searches for a variety of sources of ultra-high energy neutrinos: TeV-PeV diffuse sources by measuring either muon tracks or cascades, neutrinos in excess of PeV by searching for muons traveling in the down-going direction and point sources.

Opportunity of the solar flares (SFs) prediction observing the solar neutrino fluxes is investigated. In three neutrino generations, the evolution of the neutrino flux traveling the coupled sunspots (CSs) which are the SF source is considered. It is assumed that the neutrinos possess both the dipole magnetic moment and the anapole moment while the magnetic field above the CSs may reach the values $10^5\text{–}10^6$ Gs, display the twisting nature and posses the nonpotential character. The possible resonance conversions of the solar neutrino flux are examined. Since the ${\nu }_{eL}\to {\nu }_{\mu L}$ resonance takes place before the convective zone, its existence can in no way be connected with the SF. However, when the solar neutrino flux moves through the CSs in the preflare period, then it may undergo the additional resonance conversions and, as a result, depleting the electron neutrinos flux may be observed.

Theory predicts a neutrino signal is possible from jets from active galactic nuclei (AGN) if there is hadronic acceleration in the jets. Flaring activity in X-rays and γ-rays from blazars could indicate similar activity in neutrinos in the jets. Short duration flares, on the scale of hours, could allow for narrow time windows to be searched for a Neutrino signal above the background of atmospheric neutrinos. A wavelet technique will be run over orbit-by-orbit Swift BAT (Burst Alert Telescope) data to identify flaring periods to accurately determine start and end times. The wavelet technique is notable as it accounts for both uneven time sampling and varying error bars across a time series.

The detection of a cosmic neutrino flux by the IceCube telescope triggers the search for the astrophysical accelerators responsible for it. Among them, Galactic sources are expected to contribute at some level: thanks to its location in the Northern hemisphere, KM3NeT is optimally suited to constrain their contribution with a clean event sample of upgoing muon tracks. Therefore, it is timely to investigate the discovery potential of KM3NeT to extended sources of very-high-energy neutrinos. The study presented is based on a comparative analysis of the sensitivity of KM3NeT and CTA. The methods are then applied to two interesting Galactic gamma-ray sources: the brightest TeV supernova remnant, RX J1713.7-3946, and the Galactic Center Ridge.

The ANTARES Collaboration is building an underwater neutrino telescope in the Mediterranean Sea, at a depth of 2500 m, 40 km offshore Toulon (France). The main goal of the detector is the search for high energy neutrinos from Galactic and extra-Galactic sources as well as from the decay of neutralinos and other exotic particles. The present status of the detector, with the first five lines in acquisition since January 2007, is presented.

If non-baryonic dark matter exists in the form of neutralinos, a neutrino flux is expected from the decay of neutralino pair annihilation products inside heavy celestial bodies. Data taken with the AMANDA-II neutrino telescope located at the South Pole, have been used in a search for this indirect dark matter signal. Results are presented from searches for neutralinos accumulated in the Sun, using AMANDA-II data from 2001, and in the centre of the Earth, using AMANDA-II data from 2001 to 2003. Future perspectives, in view of higher statistics data samples acquired during recent years and by the combined AMANDA-IceCube detector, are also discussed.

The quest to understand the nature dark matter is one of the most relevant ones in Particle Physics nowadays, since it constitutes most of the matter of the Universe and it is still unknown what it is made of. In order to answer to this question, a multi-front attack is needed because our knowledge of its properties is very incomplete. Among the different experimental strategies, neutrino telescopes are very relevant tools. There are several promising sources to look at: the Sun, the Galactic Center, the Earth, dwarf galaxies, galaxy clusters… As an example of the power of neutrino telescopes, we can mention the analysis of the Sun, which offers the best sensitivity for spin dependent WIMP-nucleon scattering and is free of alternative astrophysical interpretations. In this talk I will review the status and prospects of the main present and future neutrino telescopes: ANTARES, IceCube and KM3NeT.

If non-baryonic dark matter exists in the form of neutralinos, a neutrino flux is expected from the decay of neutralino pair annihilation products inside heavy celestial bodies. Data taken with the AMANDA (Antarctica Muon and Neutrino Detector Array) neutrino telescope located at the South Pole have been used in a search for this indirect dark matter signal. We present result from searches for neutralinos accumulated in the Sun and in the centre of the Earth, using the data taken up to 2003.

The IceCube neutrino detector is being deployed at the South Pole since 2006. This cubic kilometer observatory with 80 strings of 60 photomultipliers will be completed in 2011. The data taken in 2007 with 22 strings have been used in the search for neutrino signal from neutralinos in the Sun. Preliminary results of this analysis will be shown. The planned IceCube detector will be complemented with a dense inner core, Deep Core, to improve the sensitivity in the GeV-TeV energy domain. We will also discuss the expected performance of the combined IceCube - Deep Core detector in relation to dark matter searches.

The origin of highest energy cosmic rays remains unresolved. High-energy neutrinos may provide the clues to fundamental phenomena such as the origin of cosmic rays or dark matter in the Universe. The IceCube Neutrino Observatory, a km scale neutrino detector, has come into full operation in 2011. At the highest energy levels, prototypes of a new experiment, the Askaryan Radio Array, have been deployed and are being tested. We report on the status, first results and prospects of the experimental neutrino searches under way and planned at the South Pole.