Breakdown of Stokes-Einstein relation in supercooled water

Water displays breakdown of the Stokes-Einstein relation at low temperatures. We hypothesize that the breakdown is a result of the structural changes and a sharp rise in dynamic heterogeneities that occurs low T upon crossing the Widom line.Comment: 5 Pages, 2 Figure

Decentralization of a Machine: Some Definitions

We define some notions of the decentralization of a deterministic input-output machine. This opens the possibility for introducing game-theoretic elements -- such as strategic players -- inside the machine, as part of its design.Comment: 8 page

Bounds on the Information Rate of Quantum Secret Sharing Schemes

An important metric of the performance of a quantum secret sharing scheme is its information rate. Beyond the fact that the information rate is upper bounded by one, very little is known in terms of bounds on the information rate of quantum secret sharing schemes. Further, not every scheme can be realized with rate one. In this paper we derive new upper bounds for the information rates of quantum secret sharing schemes. We show that there exist quantum access structures on $n$ players for which the information rate cannot be better than $O((\log_2 n)/n)$. These results are the quantum analogues of the bounds for classical secret sharing schemes proved by Csirmaz.Comment: 5 pages, LaTe

On the Relationship Between Dual Photography and Classical Ghost Imaging

Classical ghost imaging has received considerable attention in recent years because of its remarkable ability to image a scene without direct observation by a light-detecting imaging device. In this article, we show that this imaging process is actually a realization of a paradigm known as dual photography, which has been shown to produce full-color dual (ghost) images of 3D objects with complex materials without using a traditional imaging device. Specifically, we demonstrate mathematically that the cross-correlation based methods used to recover ghost images are equivalent to the light transport measurement process of dual photography. Because of this, we are able to provide a new explanation for ghost imaging using only classical optics by leveraging the principle of reciprocity in classical electromagnetics. This observation also shows how to leverage previous work on light transport acquisition and dual photography to improve ghost imaging systems in the future.Comment: 6 page

Properness of moment maps for representations of quivers

In this note, we give a necessary and sufficient condition for the properness of moment maps for representations of quivers. We show that the moment map for the representations of a quiver is proper if and only if the quiver is acyclic, that is, it does not contain any oriented cycle.Comment: Section 1 of this article recalls the definitions and notations from arxiv:1711.04108, of which the author is a joint author. Therefore, there is some text overlap between this article and arxiv:1711.0410

Relation Between Surface Codes and Hypermap-Homology Quantum Codes

Recently, a new class of quantum codes based on hypermaps were proposed. These codes are obtained from embeddings of hypergraphs as opposed to surface codes which are obtained from the embeddings of graphs. It is natural to compare these two classes of codes and their relation to each other. In this context two related questions are addressed in this paper: Can the parameters of hypermap-homology codes be superior to those of surface codes and what is precisely the relation between these two classes of quantum codes? We show that a canonical hypermap code is identical to a surface code while a noncanonical hypermap code can be transformed to a surface code by CNOT gates alone. Our approach is constructive; we construct the related surface code and the transformation involving CNOT gates.Comment: 9 pages, LaTeX. Revised title, abstract and introduction. Minor changes in presentatio

A new protocol implementing authentication transformations for multi-located parties

This paper discusses a new protocol implementing authentication in a multi-located environment that avoids man-in-the-middle (MIM) attack, replay attack and provides privacy, integrity of a message for multi-located parties. The protocol uses the concept that each party is associated with a subsidiary agent.Comment: 10 page

Methylammonium Lead Trihalide Perovskite Solar Cell Semiconductors Are Not Organometallic

Methylammonium lead trihalide perovskite solar cells (CH3NH3PbY3, where Y = I(3-x)Brx=1-3, I(3-x)Clx=1-3, Br(3-x)Cl x=1-3, and IBrCl) are photonic semiconductors. Researches on various fundamental and technological aspects of these materials are extensively on-going to make them stable environmentally and for commercialization. Research studies addressing these materials as organometallic are massively and repeatedly appearing in very reputable, highly cited and high impact peer-reviewed research publications, including, for example, Energy and Environmental Science, Nature Chemistry, Nature Communication, Advanced Materials, Science, ACS Nano, and many other chemistry and materials based journals of the Wiley, Elsevier, Springer and Macmillan Publishers, and the Royal and American Society Sciences. Herein, we candidly addresses the question: whether should scientists in the perovskite and nanomaterials science communities refer CH3NH3PbY3 and their mixed halogen derivatives as organometallic

A Secret Common Information Duality for Tripartite Noisy Correlations

We explore the duality between the simulation and extraction of secret correlations in light of a similar well-known operational duality between the two notions of common information due to Wyner, and G\'acs and K\"orner. For the inverse problem of simulating a tripartite noisy correlation from noiseless secret key and unlimited public communication, we show that Winter's (2005) result for the key cost in terms of a conditional version of Wyner's common information can be simply reexpressed in terms of the existence of a bipartite protocol monotone. For the forward problem of key distillation from noisy correlations, we construct simple distributions for which the conditional G\'acs and K\"orner common information achieves a tight bound on the secret key rate. We conjecture that this holds in general for non-communicative key agreement models. We also comment on the interconvertibility of secret correlations under local operations and public communication.Comment: 12 pages, 1 figure, v3: Improved readabilit

Kernel methods library for pattern analysis and machine learning in python

Kernel methods have proven to be powerful techniques for pattern analysis and machine learning (ML) in a variety of domains. However, many of their original or advanced implementations remain in Matlab. With the incredible rise and adoption of Python in the ML and data science world, there is a clear need for a well-defined library that enables not only the use of popular kernels, but also allows easy definition of customized kernels to fine-tune them for diverse applications. The kernelmethods library fills that important void in the python ML ecosystem in a domain-agnostic fashion, allowing the sample data type to be anything from numerical, categorical, graphs or a combination of them. In addition, this library provides a number of well-defined classes to make various kernel-based operations efficient (for large scale datasets), modular (for ease of domain adaptation), and inter-operable (across different ecosystems). The library is available at https://github.com/raamana/kernelmethods.Comment: 6 pages, 3 code examples, 1 tabl