Derivation of Einstein Cartan theory from general relativity

This work derives the elements of classical Einstein Cartan theory (EC) from classical general relativity (GR) in two ways. (I) Derive translational holonomy and the spin torsion field equation of EC for one Kerr mass in GR. (II) Derive the field equations of EC as the continuum limit of a sequence of discrete distributions of Kerr masses in classical GR with no electric charge. his derivation does not extend to the quantum domain because of inequality constraints. The convergence computations employ epsilon delta arguments, and are not as rigorous as weak convergence in Sobolev norm. Derivation of EC from GR strengthens the case for new physics derived from EC, including modeling exchange of intrinsic and orbital angular momentum, removing some gravitational singularities from Big Bang and black hole models, introducing a spin contact force that is a geometric candidate for the origin of cosmic inflation, and providing a better classical limit for theories of quantum gravity.Comment: 47 pages, 1 table, 66 equations, 3 figures, 93 lines of computer algebra, 33 references. This version improves organization and many sections. It argues that deriving EC from GR greatly strengthens the case for new physics that is derived from EC; the new physics is listed. Section 2 updates the 1986 paper below. Petti RJ, 1986, Gen Rel Grav vol 18, 441-46

For-Profit Education in the United States: A Primer

Higher education during the twentieth century underwent drastic changes as reformers forcefully argued education was the business of the state, and society could be improved by strong, publicly backed schools (Coulson 1999). Often proponents of state-sponsored education on the left argued the government should use education as a way to shape the minds of the nation's citizens, who were not responsible enough to take care of their own education properly (Coulson 1999). On the right, similar arguments were used as special interest groups saw the government as a means to influence what went on in the classroom. Consequently, the government stepped into the higher education arena, in part, by arguing people were not competent enough to oversee their own education. While the data for this period are scarce, it is safe to say for the period 1890 -- 1972, for-profit colleges were increasingly marginalized by the growth of highly subsidized public institutions (Breneman et al. 2006; Kinser 2006; Ruch 2001).Starting in the mid-1970s and accelerating through the 1980s and 1990s, for-profit education underwent a renaissance, due in large part to the 1972 reauthorization of the Higher Education Act, which increased the amount of government student aid available to for-profit schools (Kinser 2006; Turner 2006). During this era, the broadened scope of Pell Grants gave rise to an increasing number of for-profit universities offering associates, bachelors, and graduate degrees (Turner 2006). Since 1976, for-profit enrollment has grown at an annualized growth rate of about 11 percent, increasing by a factor of nearly twenty-three. For-profits'market share of higher education has gone from 0.4 percent to nearly 6 percent (U.S. Department of Education, National Center for Education Statistics, 2006a). The robust resurgence of for-profit schools suggests America's nonprofit colleges are failing to meet fully the people's needs. As a result, for-profits are stepping in to meet market demands their highly subsidized counterparts have chronically failed to satisfy. These recent and rapid developments have once again brought for-profit education national visibility

Domino tilings with barriers

In this paper, we continue the study of domino-tilings of Aztec diamonds. In particular, we look at certain ways of placing ``barriers'' in the Aztec diamond, with the constraint that no domino may cross a barrier. Remarkably, the number of constrained tilings is independent of the placement of the barriers. We do not know of a combinatorial explanation of this fact; our proof uses the Jacobi-Trudi identity.Comment: 5 pages (two-column format), 1 figur

Towards Neural Machine Translation with Latent Tree Attention

Building models that take advantage of the hierarchical structure of language without a priori annotation is a longstanding goal in natural language processing. We introduce such a model for the task of machine translation, pairing a recurrent neural network grammar encoder with a novel attentional RNNG decoder and applying policy gradient reinforcement learning to induce unsupervised tree structures on both the source and target. When trained on character-level datasets with no explicit segmentation or parse annotation, the model learns a plausible segmentation and shallow parse, obtaining performance close to an attentional baseline.Comment: Presented at SPNLP 201

Environmental Influences in SGRs and AXPs

Soft gamma-ray repeaters (SGRs) and anomalous x-ray pulsars (AXPs) are young (<100 kyr), radio-quiet, x-ray pulsars which have been rapidly spun-down to slow spin periods clustered at 5-12 s. Nearly all of these unusual pulsars also appear to be associated with supernova shell remnants (SNRs) with typical ages <20 kyr. If the unusual properties of SGRs and AXPs were due to an innate feature, such as a superstrong magnetic field, then the pre-supernova environments of SGRs and AXPs should be typical of neutron star progenitors. This is not the case, however, as we demonstrate that the interstellar media which surrounded the SGR and AXP progenitors and their SNRs were unusually dense compared to the environments around most young radio pulsars and SNRs. Thus, if these SNR associations are real, the SGRs and AXPs can not be ``magnetars'', and we suggest instead that the environments surrounding SGRs and AXPs play a controlling role in their development.Comment: 5 pages with 2 figures. To appear in the proceedings of the 5th Huntsville GRB Symposium (Huntsville, AL, Oct. 1999