1,259 research outputs found
Polarization of the Microwave Background in Defect Models
We compute the polarization power spectra for global strings, monopoles,
textures and nontopological textures, and compare them to inflationary models.
We find that topological defect models predict a significant (1 microK)
contribution to magnetic type polarization on degree angular scales, which is
produced by the large vector component of the defect source. We also
investigate the effect of decoherence on polarization. It leads to a smoothing
of acoustic oscillations both in temperature and polarization power spectra and
strongly suppresses the cross-correlation between temperature and polarization
relative to inflationary models. Presence or absence of magnetic polarization
or cross-correlation would be a strong discriminator between the two theories
of structure formation and will be testable with the next generation of CMB
satellites.Comment: 4 pages, 3 figures, RevTeX fil
Signature of Quantum Hall Effect Skyrmions in Tunneling: A Theoretical Study
We present a theoretical study of the tunneling characteristic between
two parallel two-dimensional electron gases in a perpendicular magnetic field
when both are near filling factor . Finite-size calculations of the
single-layer spectral functions in the spherical geometry and analytical
expressions for the disk geometry in the thermodynamic limit show that the
current in the presence of skyrmions reflects in a direct way their underlying
structure. It is also shown that fingerprints of the electron-electron
interaction pseudopotentials are present in such a current.Comment: 4 pages, 1 figur
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