Dreibein as prepotential for three-dimensional Yang-Mills theory

We advocate and develop the use of the dreibein (and the metric) as prepotential for three-dimensional SO(3) Yang-Mills theory. Since the dreibein transforms homogeneously under gauge transformation, the metric is gauge invariant. For a generic gauge potential, there is a unique dreibein on fixing the boundary condition. Topologically non-trivial monopole configurations are given by conformally flat metrics, with scalar fields capturing the monopole centres. Our approach also provides an ansatz for the gauge potential covering the topological aspects.Comment: 13 pages, improved version, section on Jacobian remove

Instability in scalar channel of fermion-antifermion scattering amplitude in massless QED_3 and anomalous dimensions of composite operators

Instability in the scalar channel of the fermion-antifermion scattering amplitude in massless QED_3 for number of flavours less than the critical value 128/3\pi^2 is demonstrated. The anomalous dimensions of gauge-invariant composite operators are determined to O(1/N). Exponentiation of the O(1/N) infrared logarithm is explicitly demonstrated by evaluating the contribution of the ladder diagrams.Comment: 10 pages, uses axodraw.sty; minor additions, version to appear in Mod. Phys. Lett.

External leg amputation in conformal invariant three-point function

Amputation of external legs is carried out explicitly for the conformal invariant three-point function involving two spinors and one vector field. Our results are consistent with the general result that amputing an external leg in a conformal invariant Green function replaces a field by its conformal partner in the Green function. A new star-triangle relation, involving two spinors and one vector field, is derived and used for the calculation.Comment: 16 pages; last paragraph added in Sec. 10, presentation improved, to appear in Eur. Phys. J.

Experimental Quantification of Entanglement Through Heat Capacity

A new experimental realization of heat capacity as an entanglement witness (EW) is reported. Entanglement properties of a low dimensional quantum spin system are investigated by heat capacity measurements performed down to very low temperatures (400mK), for various applied magnetic field values. The experimentally extracted results for the value of heat capacity at zero field matches perfectly with the theoretical estimates of entanglement from model Hamiltonians. The studied sample is a spin $\frac{1}{2}$ antiferromagnetic system which shows clear signature of quantum phase transition (QPT) at very low temperatures when the heat capacity is varied as a function of fields at a fixed temperature. The variation of entanglement as a function of field is then explored in the vicinity of the quantum phase transition to capture the sudden loss of entanglement.Comment: 8 pages, 6 figures, To be published in NJ

Criterion for dynamical chiral symmetry breaking

The Bethe-Salpeter equation is related to a generalized quantum-mechanical Hamiltonian. Instability of the presumed vacuum, indicated by a tachyon, is related to a negative energy eigenstate of this Hamiltonian. The variational method shows that an arbitrarily weak long-range attraction leads to chiral symmetry breaking, except in the scale-invariant case when the instability occurs at a critical value of the coupling. In the case of short-range attraction, an upper bound for the critical coupling is obtained.Comment: 10 pages, 2 figures; made minor changes, published versio

Evolution of Multipolar Magnetic Fields in Isolated Neutron Stars and its effect on Pulsar Radio Emission

The evolution of the multipolar structure of the magnetic field of isolated neutron stars is studied assuming the currents to be confined to the crust. Lower orders ($\le 25$) of multipole are seen to evolve in a manner similar to the dipole suggesting little or no evolution of the expected pulse shape. We also study the multifrequency polarization position angle traverse of PSR B0329+54 and find a significant frequency dependence above 2.7 GHz. We interpret this as an evidence of strong multipolar magnetic field present in the radio emission region.Comment: 2 pages, 2 figures, uses newpasp.sty, to appear in ASP Conf. Series, IAU Coll. 177 on Pulsar Astronomy-2000 and Beyond, ed. M. Kramer, N. Wex, R. Wielebinsk

Utensils-The Major Non-Ferrous Industry of India

Aluminium and brass domestic utensils are major products of the Indian non- ferrous industry amounting to 80 per cent of the total consumption of these metals in India. The utensils industry is thus a much more significant part of the non-ferrous metal industry in India than elsewhere in the world. The annual production of brass utensils is over 40,000 tons, of which only 7000 tons are produced in registered factories , the balance being manufactured by the cottage industries. Aluminium utensils, on the other hand, are mostly manufactured in factories, the annual production being estimated at over 12,000 tons . India is an exporter of aluminium wares and utensils ( 978 tons worth Rs. 61 lakhs in 1951 ) and brass wares and utensils ( worth Rs. 35 lakhs in 1951 ) mostly to the East African, Middle Eastern and South Asian countries. Production of aluminium and copper in India is not able at present to meet the demands of industry and has to be augmented by imports to the tune of Rs. 750 lakhs ( including zinc). Aluminium is the only non-ferrous metal production of which can be readily increased to any large extent in India ; this is being organized under the country's first Five Year Plan. From the point of view of national economics it is necessary that for utensils copper alloys be replaced by aluminium and its alloys in so far as this can be done without any prejudice to the indigenous manufacture of copper.This replacement could be easily effected if conservatism and antipathy of consumers against aluminium utensils could be eradicated by suitable publicity accompanied by improved design and manufacture of aluminium utensils. The need for technical control and standardization is emphasized