56,888 research outputs found
The Interacting String
We present a procedure for computing gauge-invariant scattering amplitudes in
the string, and use it to calculate three-point and four-point functions.
We show that non-vanishing scattering amplitudes necessarily involve external
physical states with excitations of ghosts as well as matter fields. The
crossing properties of the four-point functions are studied, and it is shown
that the duality of the Virasoro string amplitudes generalises in the
string, with different sets of intermediate states being exchanged in different
channels. We also exhibit a relation between the scattering amplitudes of the
string and the fusion rules of the Ising model.Comment: (Revised version), 26 pages, Plain Tex, CTP TAMU-86/92, KUL-TF-92/4
Anomaly Freedom and Realisations for Super- Strings
We construct new multi-field realisations of the super- algebra,
which are important for building super- string theories. We derive the
structure of the ghost vacuum for such theories, and use the result to
calculate the intercepts. These results determine the conditions for physical
states in the super- string theory.Comment: 22 page
Souvenirs De Guerre: Memories of War
Major Harry Pople is one of the few junior officers to have written a detailed account of his service as a platoon commander in Italy. Originally written for the journal of the Royal 22nd Regiment, La Citadelle, his memoirs are presented as a commentary on more official accounts
25th Dynasty
The era of the 25th Dynasty during the eighth and seventh centuries BCE witnessed the annexation of Egypt by kings from the neighboring land of Kush. The phrase “Twenty-fifth Dynasty” may therefore refer to either this family of royals, the state they commanded, or the historical period of their rule, but in each case research has consistently focused on the regime’s foreign aspect and its possible effects. The sequence of discovery has also proven especially consequential: not only have sources known first to scholarship shaped the interpretation of evidence found later, but the modern political contexts of those earliest discoveries have left a lasting and often misleading impression upon subsequent understanding of the period. As a result, fundamental assumptions made by scholars during the nineteenth and twentieth centuries have been drawn into question during the twenty-first century through a reevaluation of that evidence, particularly in debates related to the dynasty’s origins, chronology, and statecraft
Unfinished Business: Are Today’s P2P Networks Liable for Copyright Infringement?
In June 2005, the U.S. Supreme Court issued the decision in Metro-Goldwyn-Mayer Studios v. Grokster Ltd., a case that asked whether peer-to-peer networks may be held liable for facilitating the illegal distribution of music over the internet. The music industry petitioned the Supreme Court to settle the disagreement between the circuit courts over the standard of liability for aiding in copyright infringement. The case was based on a clash between the protection of technological innovation and the protection of artistic works. This iBrief examines the circuit split and the Grokster opinion and discusses the questions of liability left unresolved by the Supreme Court. It argues that further clarification of the Sony rule is still needed in order to encourage the proliferation of legitimate peer-to-peer networks by protecting their services while discouraging illegitimate file-sharing activities
Book Reviews: For Whom Do the Moral Theologians Speak?, Charles E. Curran, Loyal Dissent: Memoir of a Catholic Theologian, Orbis Press, 2006
The Complete Spectrum of the String
We obtain the complete physical spectrum of the string, for arbitrary
. The constraints freeze coordinates, while the remaining
coordinates appear in the currents only {\it via} their energy-momentum tensor.
The spectrum is then effectively described by a set of ordinary Virasoro-like
string theories, but with a non-critical value for the central charge and a
discrete set of non-standard values for the spin-2 intercepts. In particular,
the physical spectrum of the string includes the usual massless states of
the Virasoro string. By looking at the norms of low-lying states, we find
strong indications that all the strings are unitary.Comment: 28 page
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