80,568 research outputs found
Bucking the trend: part-time Master’s students at the University of Northampton
Nick Petford, Vice Chancellor of the University of Northampton, and Nick Allen, Executive Officer at the University of Northampton, explain how their institution has bucked the decline in part-time study for postgraduates and push the benefits of working with local industry partners on bespoke programmes
Canonical formulas for k-potent commutative, integral, residuated lattices
Canonical formulas are a powerful tool for studying intuitionistic and modal
logics. Actually, they provide a uniform and semantic way to axiomatise all
extensions of intuitionistic logic and all modal logics above K4. Although the
method originally hinged on the relational semantics of those logics, recently
it has been completely recast in algebraic terms. In this new perspective
canonical formulas are built from a finite subdirectly irreducible algebra by
describing completely the behaviour of some operations and only partially the
behaviour of some others. In this paper we export the machinery of canonical
formulas to substructural logics by introducing canonical formulas for
-potent, commutative, integral, residuated lattices (-).
We show that any subvariety of - is axiomatised by canonical
formulas. The paper ends with some applications and examples.Comment: Some typo corrected and additional comments adde
Starobinsky-type Inflation in Dynamical Supergravity Breaking Scenarios
In the context of dynamical breaking of local supersymmetry (supergravity),
including the Deser-Zumino super-Higgs effect, for the simple but quite
representative cases of N=1, D=4 supergravity, we discuss the emergence of
Starobinsky-type inflation, due to quantum corrections in the effective action
arising from integrating out gravitino fields in their massive phase. This type
of inflation may occur after a first-stage small-field inflation that
characterises models near the origin of the one-loop effective potential, and
it may occur at the non-trivial minima of the latter. Phenomenologically
realistic scenarios, compatible with the Planck data, may be expected for the
conformal supergravity variants of the basic model.Comment: Five pages pdflatex, three pdf figures incorporate
Dynamical Supergravity Breaking via the Super-Higgs Effect Revisited
We investigate the dynamical breaking of local supersymmetry (supergravity),
including the Deser-Zumino super-Higgs effect, via the corresponding one-loop
effective potential for the simple but quite representative cases of N=1, D=4
simple supergravity and a (simplified) conformal version of it. We find
solutions to the effective equations which indicate dynamical generation of a
gravitino mass, thus breaking supergravity. In the case of conformal
supergravity models, the gravitino mass can be much lower than the Planck
scale, for global supersymmetry breaking scales below the Grand Unification
scale. The absence of instabilities in the effective potential arising from the
quantum fluctuations of the metric field is emphasised, contrary to previous
claims in the literature.Comment: 24 pages, revtex, 4 pdf figures incorporate
Inflation via Gravitino Condensation in Dynamically Broken Supergravity
Gravitino-condensate-induced inflation via the super-Higgs effect is a
UV-motivated scenario for both inflating the early universe and breaking local
supersymmetry dynamically, entirely independent of any coupling to external
matter. As an added benefit, this also removes the (as of yet unobserved)
massless Goldstino associated to global supersymmetry breaking from the
particle spectrum. In this review we detail the pertinent properties and
outline previously hidden details of the various steps required in this context
in order to make contact with current inflationary phenomenology. The class of
models of SUGRA we use to exemplify our approach are minimal four-dimensional
N=1 supergravity and conformal extensions thereof (with broken conformal
symmetry). Therein, the gravitino condensate itself can play the role of the
inflaton, however the requirement of slow-roll necessitates unnaturally large
values of the wave-function renormalisation. Nevertheless, there is an
alternative scenario that may provide Starobinsky-type inflation, occurring in
the broken-SUGRA phase around the non-trivial minima of the
gravitino-condensate effective potential. In this scenario higher curvature
corrections to the effective action, crucial for the onset of an inflationary
phase, arise as a result of integrating out massive quantum gravitino fields in
the path integral. The latter scenario is compatible with Planck satellite
phenomenology but not with BICEP2 data.Comment: 27 pages, pdflatex, 7 pdf figures incorporated, contains special
macros (world scientific IJMPD); Invited Review, special issue IJMPD on
Inflatio
Response to Sean Wilentz, Against Exceptionalism: Class Consciousness and the American Labor Movement, 1790-1920
[Excerpt] Wilentz\u27s critique of the exceptionalist theme in American historiography is to the point. Whether one applauded the absence of feudalism, and therefore class conflict, in America with the historians of the 1950s or bemoaned that liberal democratic tradition as the nail in the coffin of class consciousness in the 1970s, either interpretative structure sacrifices empirical evidence for grand theory. In the former, the careers of Thomas Skidmore or Ira Stewart are all but incomprehensible; in the latter, men like Joseph R. Buchanan or Eugene V. Debs have little relevance. More importantly, the actual experience of the majority of American working people is either lost or misunderstood. For as Wilentz sharply delineates, the fact that American workers did not largely espouse an a priori notion of class did not mean that they either embraced the ideology of their employers or were defenseless, in the political culture, when confronted by the demands of those same employers on the shop floor. In exploring the continued power of America\u27s democratic revolutionary heritage for working people in the generations following 1776, Wilentz emphasizes a central concern of many workers that, the evidence would suggest, structured much of their response to industrial capitalism
[Review of the Book \u3ci\u3ePerspectives on American Labor History: The Problems of Synthesis\u3c/i\u3e]
[Excerpt] Over the past two decades many claims have been made for what was once called the new labor history. Deeply influenced by European scholarship (especially by the British historian, E. P. Thompson) and by writings in cultural anthropology and sociology, this new history seemed to sweep all before it. In a tumble of discrete community studies and precise examinations of individual strikes lay the foundation of the new history\u27s critique of the work of John K Commons and his associates, who had stressed an institutional analysis of labor\u27s growth and development within a liberal, democratic capitalist society. In studying workers outside the labor movement, in exploring their cultures and values, and in asserting the presence of explicit class tension, these works proclaimed, collectively, a new era in the study of the American working class
Two Tales of a City: Nineteenth-Century Black Philadelphia
[Excerpt] In the tension between Forging Freedom and Roots of Violence certain themes present themselves for further research and thought. Neither volume successfully analyzes the historical roots of the African-American class structure. This is especially evident in each book\u27s treatment of the black middling orders. While neither defines the category with clarity, their basic assumption that small shopkeepers and regularly employed workers were critical to the community\u27s ability to withstand some of the worst shocks of racism is important. The clash between these books also raises questions concerning the role of pre-industrial cultural values in the transition to industrial capitalism. Nash notes, and then fails to explore, the significance of black exclusion from industrial life; Lane, however, is quite clear that to be excluded from that transition, despite the pains inclusion brought, is to remain in a position of profound disadvantage. The work of Lane and William Julius Wilson suggests avenues for both historical and contemporary exploration of the economic and cultural effects of this exclusion. In addition, Lane\u27s argument has a particular implication for the writing of nineteenth-century white working-class history as well. It would lend support to the suggestions of Richard Stott and others that we need to be more rigorous in appreciating both the cultural and social values of the pre-industrial world and the specific relevance of those values to industrial society.
Finally, there is the central tension between these two books, one that revolves around their respective visions of nineteenth-century African-American urban culture. While neither argument is fully convincing, the structure of Roger Lane\u27s analysis, if not always its development, suggests an important direction for future work. Not to explore these issues historically is to continue the timidity Wilson so sharply criticized in contemporary policy debates. As in so many other areas, it was W.E.B. DuBois who pointed the way when he wrote, in 1899, that we must study, we must investigate, we must attempt to solve; and the utmost that the world can demand is, not lack of human interest and moral conviction, but rather the heart-quality of fairness, and an earnest desire for the truth despite its possible unpleasantness
- …