15,139 research outputs found

    Poisson Algebra of Wilson Loops and Derivations of Free Algebras

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    We describe a finite analogue of the Poisson algebra of Wilson loops in Yang-Mills theory. It is shown that this algebra arises in an apparently completely different context; as a Lie algebra of vector fields on a non-commutative space. This suggests that non-commutative geometry plays a fundamental role in the manifestly gauge invariant formulation of Yang-Mills theory. We also construct the deformation of the loop algebra induced by quantization, in the large N_c limit.Comment: 20 pages, no special macros necessar

    Parton Model from Bi-local Solitonic Picture of the Baryon in two-dimensions

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    We study a previously introduced bi-local gauge invariant reformulation of two dimensional QCD, called 2d HadronDynamics. The baryon arises as a topological soliton in HadronDynamics. We derive an interacting parton model from the soliton model, thus reconciling these two seemingly different points of view. The valence quark model is obtained as a variational approximation to HadronDynamics. A succession of better approximations to the soliton picture are obtained. The next simplest case corresponds to a system of interacting valence, `sea' and anti-quarks. We also obtain this `embellished' parton model directly from the valence quark system through a unitary transformation. Using the solitonic point of view, we estimate the quark and anti-quark distributions of 2d QCD. Possible applications to Deep Inelastic Structure Functions are pointed out.Comment: 12 page

    The Carath\'eodory-Fej\'er Interpolation Problems and the von-Neumann Inequality

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    The validity of the von-Neumann inequality for commuting nn - tuples of 3×33\times 3 matrices remains open for n3n\geq 3. We give a partial answer to this question, which is used to obtain a necessary condition for the Carath\'{e}odory-Fej\'{e}r interpolation problem on the polydisc Dn.\mathbb D^n. In the special case of n=2n=2 (which follows from Ando's theorem as well), this necessary condition is made explicit. An alternative approach to the Carath\'{e}odory-Fej\'{e}r interpolation problem, in the special case of n=2,n=2, adapting a theorem of Kor\'{a}nyi and Puk\'{a}nzsky is given. As a consequence, a class of polynomials are isolated for which a complete solution to the Carath\'{e}odory-Fej\'{e}r interpolation problem is easily obtained. A natural generalization of the Hankel operators on the Hardy space of H2(T2)H^2(\mathbb T^2) then becomes apparent. Many of our results remain valid for any nN,n\in \mathbb N, however, the computations are somewhat cumbersome for n>2n>2 and are omitted. The inequality limnC2(n)2KGC\lim_{n\to \infty}C_2(n)\leq 2 K^\mathbb C_G, where KGCK_G^\mathbb C is the complex Grothendieck constant and C2(n)=sup{p(T):pDn,1,T1}C_2(n)=\sup\big\{\|p(\boldsymbol T)\|:\|p\|_{\mathbb D^n,\infty}\leq 1, \|\boldsymbol T\|_{\infty} \leq 1 \big\} is due to Varopoulos. Here the supremum is taken over all complex polynomials pp in nn variables of degree at most 22 and commuting nn - tuples T:=(T1,,Tn)\boldsymbol T:=(T_1,\ldots,T_n) of contractions. We show that limnC2(n)334KGC\lim_{n\to \infty}C_2(n)\leq \frac{3\sqrt{3}}{4} K^\mathbb C_G obtaining a slight improvement in the inequality of Varopoulos. We show that the normed linear space 1(n),\ell^1(n), n>1,n>1, has no isometric embedding into k×kk\times k complex matrices for any kNk\in \mathbb N and discuss several infinite dimensional operator space structures on it.Comment: This is my thesis submitted to Indian Institute of Science, Bangalore on 20th July, 201

    System Comparisons between Organic, Biodynamic, Conventional and GMO’s in cotton production & Organic, Biodynamic, Conventional systems in Soya and Wheat in Central India

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    Over the past 05 years the organic cotton production in India has grown many folds. In the conventional cotton arena the genetically modified cotton is growing at an unprecedented rate. Considering the above factors it was considered necessary to carry out a `System’ comparisons in which the four systems can be compared. Further the research hopes to answer the larger questions o Put the discussion regarding the benefits and drawbacks of organic agriculture on a rational footing; o Help to identify challenges for organic agriculture that can then be addressed systematically; o Provide physical reference points for stakeholders in agricultural research and development and thus support decision-making and agricultural policy dialogue at different levels. At the farmers level the following outcomes are expected: What happens to yields of the crops when you stop using fertilizers and pesticides ? What happens to the pests when you don’t usefertilizers and pesticides? How do the crops grow when only farmyard manure or compost is used? Can we effectively control pests in the organic and biodynamic systems using a range of botnaical sprays ? Are the biodynamic preparations effective? What are the costs of cultivation of the different systems that we are comparing? What are impacts on the qulaity of the produce in the different systems ? What are impacts on t soils of the different systems
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