The electrical response matrix of a regular 2n-gon

Consider a unit-resistive plate in the shape of a regular polygon with 2n sides, in which even-numbered sides are wired to electrodes and odd-numbered sides are insulated. The response matrix, or Dirichlet-to-Neumann map, allows one to compute the currents flowing through the electrodes when they are held at specified voltages. We show that the entries of the response matrix of the regular 2n-gon are given by the differences of cotangents of evenly spaced angles, and we describe some connections with the limiting distributions of certain random spanning forests.Comment: 10 pages, 4 figures; v2 adds more background informatio

Share Repurchases and Acquisitions: An Analysis of Which Firms Participate

Firms can transmit cash to shareholders either by paying dividends or by purchasing shares. The share purchases can be either the firm's own securities or those of another firm. Recent evidence suggests that there has been a dramatic increase in the use of these nondividend payments to shareholders. This paper reviews the theories which have been offered regarding the motivation of nondividend payments. These include taxation advantages, adjustment towards optimal debt-equity ratios, anti-takeover strategies, free cash flow (agency) considerations, signaling, and habit formation or learning. From these theories, we derive and investigate econometrically potential characteristics which predict participation in the above actions for roughly 2.000 firms in 1976 and 1984. We find the variables suggested by the various hypotheses collectively have substantial power in predicting participation in share repurchase and acquisitions. The free cash flow and habit forming arguments prove most consistent with our findings. Tests for structural change across time confirm an intercept shift consistent with dramatic increases in these activities, and fail to reject that the characteristic determinants of these actions are unchanged.

Superconducting re-entrant cavity transducer for a resonant bar gravitational radiation antenna

Copyright @ American Institute of PhysicsA 10‐GHz superconducting niobium re‐entrant cavity parametric transducer was developed for use in a cryogenic 1.5‐tonne Nb resonant bar gravitational radiation antenna. The transducer has a very high electrical Q (6×105 at 4.2 K), and was operated at high cavity fields without degrading the Q. A very high electromechanical coupling between the antenna and the transducer was therefore achieved. The highest coupling attained, constrained by the available pump power, was 0.11. If the transducer were to be operated in conjunction with a wideband impedance matching element, an antenna bandwidth comparable to the frequency of the antenna would be attained. The temperature dependence of the Q of the transducer was in good agreement with theory. At temperatures above about 6 K the Q was degraded by the increase in the BCS surface resistance, while at lower temperatures the Q was limited by radiative losses

Natural Disasters and the Yield Curve of Florida Valencias

Crop Production/Industries,

Cryptocurrencies Are Taxable and Not Free From Fraud

In this report, the authors discuss cryptocurrencies — especially bitcoin — and argue that because the IRS lists them as property, they are taxable, and because they are not as anonymous as once thought, they are not free from fraud. Cryptocurrencies are digital assets used as a medium of exchange, but they are not really coins. They can be sent electronically from one entity to another almost anywhere in the world with an internet connection. There are many cryptocurrencies in the market, including bitcoin, ethereum, ethereum classic, litecoin, nem, dash, iota, bitshares, monero, neo, and ripple. Many of the cryptocurrency networks are not controlled by a single entity or company; instead, a decentralized network of computers keeps track of the currency using a token ID. A ledger maintains a continuously growing list of date stamped transactions in real time called “blocks.” This technology is known as blockchain, which records, verifies, and stores transactions without a trusted central authority. The network instead relies on decentralized autonomous organizations (DAOs) with uncertain legal standing

How can we test seesaw experimentally?

The seesaw mechanism for the small neutrino mass has been a popular paradigm, yet it has been believed that there is no way to test it experimentally. We present a conceivable outcome from future experiments that would convince us of the seesaw mechanism. It would involve a variety of data from LHC, ILC, cosmology, underground, and low-energy flavor violation experiments to establish the case.Comment: 5 pages, 4 figure