Failing and forgetting Afghanistan [Blog post]

This is a blog post published on the LSE Gender Hub pages. As Afghanistan collapsed and crisis became imminent this was written during my work as a colleague, a humanitarian actor, a fund raiser to help with evacuating our research colleagues from the country in August 2021

Constraining Form Factors with the Method of Unitarity Bounds

The availability of a reliable bound on an integral involving the square of the modulus of a form factor on the unitarity cut allows one to constrain the form factor at points inside the analyticity domain and its shape parameters, and also to isolate domains on the real axis and in the complex energy plane where zeros are excluded. In this lecture note, we review the mathematical techniques of this formalism in its standard form, known as the method of unitarity bounds, and recent developments which allow us to include information on the phase and modulus along a part of the unitarity cut. We also provide a brief summary of some results that we have obtained in the recent past, which demonstrate the usefulness of the method for precision predictions on the form factors.Comment: 12 pages, 2 figures; Lecture given at the DAE-BRNS Workshop on Hadron Physics, Bhabha Atomic Research Centre, Mumbai, India, October 31-November 4, 2011, submitted to Proceeding

Hilbert-Schmidt Operators vs. Integrable Systems of Elliptic Calogero-Moser Type III. The Heun Case

The Heun equation can be rewritten as an eigenvalue equation for an ordinary differential operator of the form $-d^2/dx^2+V(g;x)$, where the potential is an elliptic function depending on a coupling vector $g\in{\mathbb R}^4$. Alternatively, this operator arises from the $BC_1$ specialization of the $BC_N$ elliptic nonrelativistic Calogero-Moser system (a.k.a. the Inozemtsev system). Under suitable restrictions on the elliptic periods and on $g$, we associate to this operator a self-adjoint operator $H(g)$ on the Hilbert space ${\mathcal H}=L^2([0,\omega_1],dx)$, where $2\omega_1$ is the real period of $V(g;x)$. For this association and a further analysis of $H(g)$, a certain Hilbert-Schmidt operator ${\mathcal I}(g)$ on ${\mathcal H}$ plays a critical role. In particular, using the intimate relation of $H(g)$ and ${\mathcal I}(g)$, we obtain a remarkable spectral invariance: In terms of a coupling vector $c\in{\mathbb R}^4$ that depends linearly on $g$, the spectrum of $H(g(c))$ is invariant under arbitrary permutations $\sigma(c)$, $\sigma\in S_4$

A review on Machine Learning Techniques

Machine learning is the essence of artificial intelligence. Machine Learning learns from past experiences to improve the performances of intelligent programs. Machine learning system builds the learning model that effectively “learns” how to estimate from training data of given example. IT refers to a set of topics dealing with the creation and evaluation of algorithms that facilitate pattern recognition, classification, and prediction, based on models derived from existing data. In this new era, Machine learning is mostly in use to demonstrate the promise of producing consistently accurate estimates. The main goal and contribution of this review paper is to present the overview of machine learning and provides machine-learning techniques. Also paper reviews the merits and demerits of various machine learning algorithms in different approaches

A note on the Gauss decomposition of the elliptic Cauchy matrix

Explicit formulas for the Gauss decomposition of elliptic Cauchy type matrices are derived in a very simple way. The elliptic Cauchy identity is an immediate corollary.Comment: 5 page

Secondary or Transient Pseudohypoaldosteronism Associated With Urinary Tract Anomaly and Urinary Infection: A Case Report

AbstractHyponatremia with hyperkalemia in infancy is a rare presentation, but may be due to aldosterone deficiency or end organ resistance to its action. There are few cases associating this condition with urinary tract infections or anatomic abnormalities that predispose to infection. Clinicians should have a high index of suspicion in diagnosing secondary pseudohypoaldosteronism (PHA) due to its often atypical presentation. We describe ten month-old infant who presented with this condition and was found to have urinary tract infection complicating unilateral urinary tract anomaly, which may have strong association with renal tubular resistance to aldosterone