Estimating production losses from disruptions based on stock market returns: Applications to 9/11 attacks, the Deepwater Horizon oil spill, and Hurricane Sandy

The threats to human life and infrastructure are ever growing due to global terrorism, conflicts and climate change as well as the omnipresent threat of natural disruptions like earthquakes, volcanos, tsunamis etc. Disruptions or disasters lead to sudden changes in demand, production and supply. In case of such scenarios it is essential to optimize the utilization of available resources and avoid further wastage. In this study a model is presented to measure the changes in production due to changes in supply and demand of goods and services, and measure possible losses to industries during such disruptions. It is anticipated that there is a strong economic correlation of growth among the industries and there is a ripple effect causing losses to interdependent industries and economies in such scenarios. It is believed that, variability in the economy is preceded by stock market price fluctuations. The trend of any economy is reflected in the stock markets that it encompasses and these markets provide instantaneous feedback to changes in a state of normalcy. These stock markets have been used to study the variability in economic output of industries, and measure the dynamic changes in production or output of industries. The results of the study justify the existence of such a correlation between the gross output of industries and the stock indices that are related to these industries. Study of past disruptions is performed through a deterministic model and a stochastic model and the results obtained resonate with the existing estimates published by studies measuring the economic impacts of these disruptions. Such a study would enable governments, corporations and individual businesses to make informed decisions regarding the allocation of resources and contingency plans in case of such a disruption. The risk of monetary and market losses can be substantially reduced thus enabling faster recovery and higher resilience

Hard Matching for Boosted Tops at Two Loops

Cross sections for top quarks provide very interesting physics opportunities, being both sensitive to new physics and also perturbatively tractable due to the large top quark mass. Rigorous factorization theorems for top cross sections can be derived in several kinematic scenarios, including the boosted regime in the peak region that we consider here. In the context of the corresponding factorization theorem for $e^+e^-$ collisions we extract the last missing ingredient that is needed to evaluate the cross section differential in the jet-mass at two-loop order, namely the matching coefficient at the scale $\mu\simeq m_t$. Our extraction also yields the final ingredients needed to carry out logarithmic resummation at next-to-next-to-leading logarithmic order (or N$^3$LL if we ignore the missing 4-loop cusp anomalous dimension). This coefficient exhibits an amplitude level rapidity logarithm starting at $\mathcal{O}(\alpha_s^2)$ due to virtual top quark loops, which we treat using rapidity renormalization group (RG) evolution. Interestingly, this rapidity RG evolution appears in the matching coefficient between two effective theories around the heavy quark mass scale $\mu\simeq m_t$.Comment: 35 pages, 3 figures, v2: added extraction of 3-loop anon. dimension, journal versio

Small-xx Factorization from Effective Field Theory

We derive a factorization theorem that allows for resummation of small-$x$ logarithms by exploiting Glauber operators in the soft collinear effective field theory. Our analysis is carried out for the hadronic tensor $W^{\mu\nu}$ in deep inelastic scattering, and leads to the definition of a new gauge invariant soft function $S^{\mu\nu}$ that describes quark and gluon emission in the central region. This soft function provides a new framework for extending resummed calculations for coefficient functions to higher logarithmic orders. Our factorization also defines impact factors by universal collinear functions that are process independent, for instance being identical in small-$x$ DIS and Drell-Yan.Comment: 43 pg

Germanium-on-silicon mid-infrared arrayed waveguide grating multiplexers

In this letter, we describe the use of a germanium-on- silicon waveguide platform to realize an arrayed waveguide grating (AWG) operating in the 5 mu m wavelength range, which can be used as a wavelength multiplexer for mid-infrared (midIR) light engines or as the core element of a midIR spectrometer. Ge-on-Si waveguide losses in the range 2.5-3.5 dB/cm for TE polarized light and 3-4 dB/cm for TM polarized light in the 5.15-5.4 mu m wavelength range are reported. A 200 GHz channel spacing 5-channel AWG with an insertion loss/crosstalk of 2.5/3.1 dB and 20/16 dB for TE and TM polarization, respectively, is demonstrated

Nonperturbative Corrections to Soft Drop Jet Mass

We provide a quantum field theory based description of the nonperturbative effects from hadronization for soft drop groomed jet mass distributions using the soft-collinear effective theory and the coherent branching formalism. There are two distinct regions of jet mass $m_J$ where grooming modifies hadronization effects. In a region with intermediate $m_J$ an operator expansion can be used, and the leading power corrections are given by three universal nonperturbative parameters that are independent of all kinematic variables and grooming parameters, and only depend on whether the parton initiating the jet is a quark or gluon. The leading power corrections in this region cannot be described by a standard normalized shape function. These power corrections depend on the kinematics of the subjet that stops soft drop through short distance coefficients, which encode a perturbatively calculable dependence on the jet transverse momentum, jet rapidity, and on the soft drop grooming parameters $z_{\rm cut}$ and $\beta$. Determining this dependence requires a resummation of large logarithms, which we carry out at LL order. For smaller $m_J$ there is a nonperturbative region described by a one-dimensional shape function that is unusual because it is not normalized to unity, and has a non-trivial dependence on $\beta$.Comment: 61 pages + Appendices, 26 figure

Boragaon: Amid Guwahati's Waste is a Neglected Ecosystem of People and Animals

Waste is often considered a great nuisance – but it can also be a source of livelihoods and sustenance in its own right. A big thorn in Guwahati’s side is its municipal waste, and the public dialogue over its Boragaon landfill is currently caught between urban development and ecological and public health. Yet there exists a third group with its own interests that both civil society and policymakers need to acknowledge and plan for