Surface defects from fractional branes. Part I

We show that the Gukov-Witten monodromy defects of supersymmetric Yang-Mills theory can be realized in perturbative string theory by considering an orbifold background of the Kanno-Tachikawa type and placing stacks of fractional D3-branes whose world-volume partially extends along the orbifold directions. In particular, we show that turning on a constant background value for some scalar fields in the closed string twisted sectors induces a non-trivial profile for the gauge field and one of the complex scalars of the world-volume theory, and that this profile exactly matches the singular behavior that one expects for a Gukov-Witten surface defect in the N $$\mathcal{N}$$ = 4 super Yang-Mills theory. To keep the presentation as simple as possible, in this work we restrict our analysis to surface defects corresponding to a ℤ2 orbifold and defer the study of the most general case to a companion paper

Performance of wheat cultivars at varying fertility levels under system of wheat intensification and conventional method of wheat production system

A field experiment was conducted during rabi season of 2009-10 at Ranchi, Jharkhand to evaluate the performance of wheat cultivars at varying fertility levels under system of wheat intensification and conventional method of cultivation. The morpho-physiological analysis of growth and yield in wheat revealed that system of wheatintensification manifested higher total tillers m-2, leaf area index, dry matter accumulation, crop growth rate, number of spikes m-2, grains per spike and 1000-grain weight resulting in higher grain and straw yield over conventional method of cultivation. The net return and benefit: cost ratio as well as the nutrient uptake of nitrogen, phosphorus and potash was also recorded significantly higher under system of wheat intensification. Higher fertility level of 120 kg N ha-1, 60 kg P2O5 ha-1 and 40 kg K2O ha-1 also significantly improved the plant height, total tillers m-2, leaf area index, dry matter accumulation, crop growth rate, number of spikes m-2, grains per spike, 1000-grain weight, grain yield, straw yield, net return, benefit: cost ratio and nutrient uptake of nitrogen, phosphorus and potash. Among the wheat cultivars, K 9107 manifested significant improvement in growth attributes at all the growth stages resulting in significantly higher yield attributes, grain yield, straw yield, net return, benefit: cost ratio and nutrient uptake of nitrogen, phosphorus and potash than Birsa Gehu 3, HUW 468 and K 0307. Thus it can be concluded that the wheat variety K 9107 fertilized with 120 kg N ha-1, 60 kg P2O5 ha-1 and 40 kg K2O ha-1 under System of Wheat Intensification may able to boost up the wheat productivity under irrigated ecosystem of Chhotanagpur plateau region, India

D-branes in Unoriented Non-critical Strings and Duality in SO(N) and Sp(N) Gauge Theories

We exhibit exact conformal field theory descriptions of SO(N) and Sp(N) pairs of Seiberg-dual gauge theories within string theory. The N=1 gauge theories with flavour are realized as low energy limits of the worldvolume theories on D-branes in unoriented non-critical superstring backgrounds. These unoriented backgrounds are obtained by constructing exact crosscap states in the SL(2,R)/U(1) coset conformal field theory using the modular bootstrap method. Seiberg duality is understood by studying the behaviour of the boundary and crosscap states under monodromy in the closed string parameter space.Comment: 23 pages, 2 figure

Constraints faced Panchayat Members in Relation to Agricultural Development Programs in Ujjain District (M.P.)

In india Panchayati Raj now functions as a system of governance in which Gram Panchayats are the basic units of local administration. The system has three levels: Gram Panchayat (village level), Mandal Parishad or Block Samiti or Panchayat Samiti (block level), and Zila Parishad (district level). Panchayat Raj has come to be related with two broad images. First, it is a government by itself and second it is an agency of the state government. In the integrated exercise of planning for social and economic development, co-ordinate roles, the present set up is a three-tier representative structure of government where the administrators, elected leaders and local population participate in the developmental effort. In this regard the members of Panchyat faced many problems there this study confront the constrains faced by members and suggestions to overcome them with 120 sample unit of Ujjain district. The major finding was obtained in this study that the most serious constraint perceived by the Gram Panchayat Members during agriculture development programmes was Insufficient use of communication media  (85.83%) as it was perceived to the highest extent by gram Panchayat Members with major suggestion of them Properly and timely use of communication media. View Article DOI: 10.47856/ijaast.2021.v08i9.01

Modular anomaly equations and S-duality in N=2 conformal SQCD

We use localization techniques to study the non-perturbative properties of an N = 2 $$\mathcal{N}=2$$ superconformal gauge theory with gauge group SU(3) and six fundamental flavours. The instanton corrections to the prepotential, the dual periods and the period matrix are calculated in a locus of special vacua possessing a ℤ 3 symmetry. In a semiclassical expansion, we show that these observables are constrained by S-duality via a modular anomaly equation which takes the form of a recursion relation. The solutions of the recursion relation are quasi-modular functions of Γ 1 (3), which is a subgroup of the S -duality group and is also a congruence subgroup of SL(2 , ℤ )

D-branes in Toroidal Orbifolds and Mirror Symmetry

We study D-branes extended in T^2/Z_4 using the mirror description as a tensor product of minimal models. We describe branes in the mirror both as boundary states in minimal models and as matrix factorizations in the corresponding Landau-Ginzburg model. We isolate a minimal set of branes and give a geometric interpretation of these as D1-branes constrained to the orbifold fixed points. This picture is supported both by spacetime arguments and by the explicit construction of the boundary states, adapting the known results for rational boundary states in the minimal models. Similar techniques apply to a larger class of toroidal orbifolds.Comment: 30 pages, 2 figure

Asymptotic Symmetries of String Theory on AdS3 X S3 with Ramond-Ramond Fluxes

String theory on AdS3 space-times with boundary conditions that allow for black hole states has global asymptotic symmetries which include an infinite dimensional conformal algebra. Using the conformal current algebra for sigma-models on PSU(1,1|2), we explicitly construct the R-symmetry and Virasoro charges in the worldsheet theory describing string theory on AdS3 X S3 with Ramond-Ramond fluxes. We also indicate how to construct the full boundary superconformal algebra. The boundary superconformal algebra plays an important role in classifying the full spectrum of string theory on AdS3 with Ramond-Ramond fluxes, and in the microscopic entropy counting in D1-D5 systems.Comment: 30 page

Effective superpotentials for B-branes in Landau-Ginzburg models

We compute the partition function for the topological Landau-Ginzburg B-model on the disk. This is done by treating the worldsheet superpotential perturbatively. We argue that this partition function as a function of bulk and boundary perturbations may be identified with the effective D-brane superpotential in the target spacetime. We point out the relationship of this approach to matrix factorizations. Using these methods, we prove a conjecture for the effective superpotential of Herbst, Lazaroiu and Lerche for the A-type minimal models. We also consider the Landau-Ginzburg theory of the cubic torus where we show that the effective superpotential, given by the partition function, is consistent with the one obtained by summing up disk instantons in the mirror A-model. This is done by explicitly constructing the open-string mirror map.Comment: 57p, 7 figs, harvma

B-type defects in Landau-Ginzburg models

We consider Landau-Ginzburg models with possibly different superpotentials glued together along one-dimensional defect lines. Defects preserving B-type supersymmetry can be represented by matrix factorisations of the difference of the superpotentials. The composition of these defects and their action on B-type boundary conditions is described in this framework. The cases of Landau-Ginzburg models with superpotential W=X^d and W=X^d+Z^2 are analysed in detail, and the results are compared to the CFT treatment of defects in N=2 superconformal minimal models to which these Landau-Ginzburg models flow in the IR.Comment: 50 pages, 2 figure