Platelet Collapse Model of Pulsar Glitches

A platelet collapse model of starquakes is introduced. It displays self-organized criticality with a robust power-law behavior. The simulations indicate a near-constant exponent, whenever scaling is present.Comment: Figures available by sending request to Ivan Schmidt: [email protected]

Epitaxial strain and the magnetic properties of canted antiferromagnetic perovskite NaNiF3 thin films

The perovskite crystal structure is known to exhibit a multitude of interesting physical phenomena owing to the intricate coupling of the electronic and magnetic properties to the structure. Fluoroperovskites offer an alternative chemistry to the much more widely studied oxide materials, which may prove advantageous for applications. It is demonstrated here for the first time that the antiferromagnetic perovskite fluoride, NaNiF3, can be synthesized in thin film form. The films were grown via molecular beam epitaxy on SrTiO3 (100) substrates to produce high quality epitaxial films in the thickness range of 5-50 nm. The Pnma structure of the films was confirmed by x-ray diffraction. There was a decrease in the out-of-plane lattice spacing from the bulk value corresponding to a maximum strain of 1.7% in the thinnest film. Canted antiferromagnetism was measured in all films using magnetometry and a negative change in the antiferromagnetic ordering temperature of ΔTN = - 9.1 ± 0.7 K was observed with increasing strain

Eigenvalues of the Laplacian of a graph

Let G be a finite undirected graph with no loops or multiple edges. The Laplacian matrix of G, Delta(G), is defined by Delta sub ii = degree of vertex i and Delta sub ij = -1 if there is an edge between vertex i and vertex j. The structure of the graph G is related to the eigenvalues of Delta(G); in particular, it is proved that all the eigenvalues of Delta(G) are nonnegative, less than or equal to the number of vertices, and less than or equal to twice the maximum vertex degree. Precise conditions for equality are given

The Common Law Corporation: The Power of the Trust in Anglo-American Business History

This Essay challenges a central narrative in the history of Anglo- American business by questioning the importance of the corporate form. The Essay shows that the corporate form was not, as we have long believed, the exclusive historical source of powers such as limited liability, entity shielding, tradable shares, and legal personhood in litigation. These powers were also available throughout modern history through a little-studied, but enormously important, device known as the common law trust. The trust was widely and very effectively used to hold the property of unincorporated partnerships and associations in England and the United States both long before and long after the passage of general incorporation statutes in the mid-nineteenth century. The trusts success in wielding corporation-like powers suggests that the corporations role in legal history was smaller than-or at least different from-the one we have long assigned to it. This Essay thus lays the groundwork for a new account of the corporatef orm and its place in the development of modern business

Searching for Extra Dimensions in the Early Universe

We investigate extra spatial dimensions ($D = 3+\epsilon$) in the early universe using very high resolution molecular rotational spectroscopic data derived from a large molecular cloud containing moderately cold carbon monoxide gas at Z $\approx 6.42$. It turns out that the $\epsilon$-dependent quantum mechanical wavelength transitions are solvable for a linear molecule and we present the solution here. The CO microwave data allows a very precise determination of $= -0.00000657 \pm .10003032$. The probability that $\neq 0$ is one in 7794, only 850 million years (using the standard cosmology) after the Big Bang.Comment: 17 pages, 2 figure