We determine the physical parameters (magnetic eld and Doppler factor) of the homogeneous synchrotron self-Compton model allowed by the observed X{ray to gamma-ray spectra and variability of Markarian 501 during the 15{16 April 1997 aring activity. We nd that, for 20 minute variability, a magnetic eld of 0.2 G and a Doppler factor of 20 could t these observations. We take account of photon-phot...

Universal conductance #uctuations in Cu :Mn nano-contacts of di!erent Mn concentrations c yield the phase coherence length ̧ which exhibits a minimum at c+100 ppm. Above this concentration which marks the onset of a spin-glass state below 0.2 K, ̧ depends on the magnetic "eld range, rising to nearly the c"0 value for B3[9.5, 12.5 T] and leveling-o! at a much lower value for B3[0, 3 T]. These re...

Magnetization reversal phenomena in a submicron magnetic wire with a trilayer structure were investigated by measuring the electric resistance in external magnetic "elds. The critical "eld for domain wall nucleation was observed to be slightly di!erent for each "eld sweep. The magnetoresistance measurements were repeated 200 times with a sweep rate of 6 Oe/s. The obtained distribution of critic...

A general model of magnetically controlled accretion onto T Tauri stars is presented. In this model the magnetic eld is oriented arbitrarily in relation to the star's rotation axis. The resultant interplay between the magnetic eld and accretion disc causes a variable accretion rate. The dominant timescale of this variability is the beat frequency between the stellar rotation frequency and the o...

The radial structure of a thin accretion disc is calculated in the presence of a central dipole magnetic eld aligned with the rotation axis. The problem is treated using a modiied expression for the turbulent magnetic diiusion, which allows the angular momentum equation to be integrated analytically. The governing algebraic equations are solved iteratively between 1 ? 10 4 stellar radii. An ana...

Swing-excited dynamo-induced magnetic elds in spiral galaxies are studied. We investigate the phenomenon of swing excitation with nonlinear 3D numerical simulations of the galactic dynamo. In a rst step we present a linear analysis in order to get inside in basic properties of the swing-excitation phenomenon in one and two-armed spiral galaxies. The model includes diierential rotation, axisymme...

Although Mars does not presently appear to have a global dynamo magnetic field, strong crustal fields have recently been detected by the Mars Global Surveyor above surfaces formed V3 or more Ga. We present magnetic and textural studies of Martian meteorite ALH84001 demonstrating that 4 Ga carbonates containing magnetite and pyrrhotite carry a stable natural remanent magnetization. Because 40Ar/...

We obtain the Lifschitz tail, i.e. the exact low energy asymptotics of the integrated density of states (IDS) of the two dimensional magnetic Schrr odinger operator with a uniform magnetic eld and random Poissonian impurities. The single site potential is repulsive and it has a nite but nonzero range. We show that the IDS is a continuous function of the energy at the bottom of the spectrum. Thi...

Conventionally, edges are treated as either scalar or vector quantities. This paper presents a novel framework which treats edges as directional dipoles that induce the eld around themselves. An analogy can be made between this concept and the interaction of magnetic dipoles with the magnetic eld. The dipoles interact with the eld and align themselves into a smooth contour connguration. This pa...

Mapping Mercury’s internal magnetic #eld with a magnetometer in closed orbit around the planet will provide valuable information about its internal structure. By measuring magnetic #eld multipoles of order higher than the dipole we could, in principle, determine some properties, such as size and location, of the internal source. Here we try to quantify these expectations. Using conceptual model...