Scalar Blocks as Gravitational Wilson Networks

In this paper we continue to develop further our prescription [arXiv:1602.02962] to holographically compute the conformal partial waves of CFT correlation functions using the gravitational open Wilson network operators in the bulk. In particular, we demonstrate how to implement it to compute four-point scalar partial waves in general dimension. In the process we introduce the concept of OPE modules, that helps us simplify the computations. Our result for scalar partial waves is naturally given in terms of the Gegenbauer polynomials. We also provide a simpler proof of a previously known recursion relation for the even dimensional CFT partial waves, which naturally leads us to an odd dimensional counterpart.Comment: 36 page

Enhancing Abiotic Stress Tolerance in Cereals Through Breeding and Transgenic Interventions

The success of plant breeding in the 20th century led to new cultivars that, to date, have provided enough food for an increasing world population (Conway and Toenniessen 1999; Mifflin 2000). The results of the Green Revolution-led in the 1960s by Henry M. Beachell andNormanE. Dotlaug—resulted in a dramatic increase in rice and wheal grain yields (Milford and Runge 2007; Ortiz et al. 2007). However, abiotic stresses and climate change are becoming increasingly serious threats to crop production worldwide at a time when food staple supply will need to be significantly higher to meet the demand of the growing human population. Water scarcity (Rockstrom et al. 2007], salinity (Rengasamy 2006). and low soil fertility (Sanchez and Swaminathan 2005) rank among the moat important abiotic stresses worldwide. Similarly, increased climatic disturbances due to global warming are causing the major stresses that necessitate crop improvements to safeguard grain supply, particularly in the developing world (Kumar 2006). Hence, genetic enhancement of cereal crops with respect to abiotic stress tolerance will be essential far ensuring grain yields in water-limited, increasingly hotter agricultural zones, particularly If these conditions combine with poor and saline soils, conditions that prevail in parts of the developing world. Crop breeding for adaptation to abiotic stress-prone environments remains a challenging task, not least because of the complexity of the stress-adaptive mechanisms in plants and particularly cereal crops, which are the staple of most of the world's population (Reynolds et al. 2005}

Crossing Symmetric Spinning S-matrix Bootstrap: EFT bounds

International audienceWe develop crossing symmetric dispersion relations for describing 2-2 scattering of identical external particles carrying spin. This enables us to import techniques from Geometric Function Theory and study two sided bounds on low energy Wilson coefficients. We consider scattering of photons, gravitons in weakly coupled effective field theories. We provide general expressions for the locality/null constraints. Consideration of the positivity of the absorptive part leads to an interesting connection with the recently conjectured weak low spin dominance. We also construct the crossing symmetric amplitudes and locality constraints for the massive neutral Majorana fermions and parity violating photon and graviton theories. The techniques developed in this paper will be useful for considering numerical S-matrix bootstrap in the future