194,967 research outputs found
Wind braking of magnetars: to understand magnetar's multiwave radiation properties
Magnetars are proposed to be peculiar neutron stars powered by their super
strong magnetic field. Observationally, anomalous X-ray pulsars and soft
gamma-ray repeaters are believed to be magnetar candidates. While more and more
multiwave observations of magnetars are available, unfortunately, we see
accumulating failed predictions of the traditional magnetar model. These
challenges urge rethinking of magnetar. Wind braking of magnetars is one of the
alternative modelings. The release of magnetic energy may generate a particle
outflow (i.e., particle wind), that results in both an anomalous X-ray
luminosity and significantly high spindown rate. In this wind braking scenario,
only strong multipole field is necessary for a magnetar (a strong dipole field
is no longer needed). Wind braking of magnetars may help us to understand their
multiwave radiation properties, including (1) Non-detection of magnetars in
Fermi-LAT observations, (2) The timing behaviors of low magnetic field
magnetars, (3) The nature of anti-glitches, (4) The criterion for magnetar's
radio emission, etc. In the wind braking model of magentars, timing events of
magnetars should always be accompanied by radiative events. It is worth noting
that the wind engine should be the central point in the research since other
efforts with any reasonable energy mechanism may also reproduce the results.Comment: 6 pages, 1 figure, submitted to conference proceeding of SMFNS2013
(Strong electromagnetic field and neutron stars 2013
The timing behavior of magnetar Swift J1822.3-1606: timing noise or a decreasing period derivative?
The different timing results of the magnetar Swift J1822.3-1606 is analyzed
and understood theoretically. It is pointed that different timing solutions are
caused not only by timing noise, but also that the period derivative is
decreasing after outburst. Both the decreasing period derivative and the large
timing noise may be originated from wind braking of the magnetar. Future timing
of Swift J1822.3-1606 will help us make clear whether its period derivative is
decreasing with time or not.Comment: 5 pages, 1 figure. Accepted by Research in Astronomy and Astrophysic
New results of intersection numbers on moduli spaces of curves
We present a series of new results we obtained recently about the
intersection numbers of tautological classes on moduli spaces of curves,
including a simple formula of the n-point functions for Witten's
classes, an effective recursion formula to compute higher Weil-Petersson
volumes, several new recursion formulae of intersection numbers and our proof
of a conjecture of Itzykson and Zuber concerning denominators of intersection
numbers. We also present Virasoro and KdV properties of generating functions of
general mixed and intersections.Comment: 9 pages, a brief surve
Loop Expansion in Light-Cone Field Theory
A loop expansion is implemented based on the path integral quantization of
the light-cone field theory in 1+1 dimensions. The effective potential
as a function of the zero-mode field is calculated up to two loop
order and its derivative with respect to is used to determine the
vacuum expectation value of the field . The critical coupling constant at
the spontaneous symmetry breakdown is consistent with that obtained in the
ordinary instant-form field theory. The critical exponents which describe the
behavior of the susceptibility and the vacuum expectation value of near
the critical point are evaluated from the effective potential. The one loop
diagrams for the connected Green's function are calculated in momentum space.
The relevant equal-time correlation function is shown to be closely related.Comment: 12 pages, plain Tex, 1 table, 3 figures available from
[email protected] , accepted by Phys. Rev.
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