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Arkady A Tseytlin - One of the best experts on this subject based on the ideXlab platform.
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exactly solvable model of superstring in plane wave ramond ramond background
Physical Review D, 2002Co-Authors: R R Metsaev, Arkady A TseytlinAbstract:We describe in detail the solution of type IIB superstring theory in the maximally supersymmetric plane-wave background with constant null Ramond-Ramond 5-form field strength. The corresponding light-cone Green-Schwarz action found by Metsaev is quadratic in both bosonic and fermionic coordinates. We obtain the light-cone Hamiltonian and the string representation of the corresponding supersymmetry algebra. The superstring Hamiltonian has a ``harmonic-oscillator'' form in both the string oscillator and the zero-mode parts and thus has a discrete spectrum. We analyze the structure of the zero-mode sector of the theory, establishing the precise correspondence between the lowest-lying ``massless'' string states and the type IIB supergravity fluctuation modes in the plane-wave background. The zero-mode spectrum has a certain similarity to the supergravity spectrum in ${\mathrm{AdS}}_{5}\ifmmode\times\else\texttimes\fi{}{\mathrm{S}}^{5}$ background of which the plane-wave background is a special limit. We also compare the plane-wave string spectrum with the expected form of the light-cone gauge spectrum of the ${\mathrm{AdS}}_{5}\ifmmode\times\else\texttimes\fi{}{\mathrm{S}}^{5}$ superstring.
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exactly solvable model of superstring in plane wave ramond ramond background
2002Co-Authors: R R Metsaev, Arkady A TseytlinAbstract:We describe in detail the solution of type IIB superstring theory in the maximally supersymmetric plane-wave background with constant null Ramond-Ramond 5-form field strength. The corresponding light-cone Green-Schwarz action found in hep-th/0112044 is quadratic in both bosonic and fermionic coordinates. We find the spectrum of the light-cone Hamiltonian and the string representation of the supersymmetry algebra. The superstring Hamiltonian has a ``harmonic-oscillator'' form in both the string-oscillator and the zero-mode parts and thus has discrete spectrum in all 8 transverse directions. We analyze the structure of the zero-mode sector of the theory, establishing the precise correspondence between the lowest-lying ``massless'' string states and the type IIB supergravity fluctuation modes in the plane-wave background. The zero-mode spectrum has certain similarity to the supergravity spectrum in AdS_5 x S^5 of which the plane-wave background is a special limit. We also compare the plane-wave string spectrum with expected form of the light-cone gauge spectrum of superstring in AdS_5 x S^5.
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string theory and classical absorption by three branes
Nuclear Physics, 1997Co-Authors: Steven S Gubser, Igor R Klebanov, Arkady A TseytlinAbstract:Low-energy absorption cross sections for various particles falling into extreme non-dilatonic branes are calculated using string theory and world-volume field theory methods. The results are compared with classical absorption by the corresponding gravitational backgrounds. For the self-dual three-brane, earlier work by one of us demonstrated precise agreement of the absorption cross sections for the dilaton, and here we extend the result to Ramond-Ramond scalars and to gravitons polarized parallel to the brane. In string theory, the only absorption channel available to dilatons and Ramond-Ramond scalars at leading order is conversion into a pair of gauge bosons on the three-brane. For gravitons polarized parallel to the brane, scalars, fermions and gauge bosons all make leading-order contributions to the cross section, which remarkably add up to the value predicted by classical gravity. For the two-brane and five-brane of M-theory, numerical coefficients fail to agree, signaling our lack of a precise understanding of the world-volume theory for large numbers of coincident branes. In many cases, we note a remarkable isotropy in the final state particle flux within the brane. We also consider the generalization to higher partial waves of minimally coupled scalars. We demonstrate agreement for the three-brane at l = 1 and indicate that further work is necessary to understand l > 1.
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string theory and classical absorption by threebranes
arXiv: High Energy Physics - Theory, 1997Co-Authors: Steven S Gubser, Igor R Klebanov, Arkady A TseytlinAbstract:Low energy absorption cross-sections for various particles falling into extreme non-dilatonic branes are calculated using string theory and world-volume field theory methods. The results are compared with classical absorption by the corresponding gravitational backgrounds. For the self-dual threebrane, earlier work by one of us demonstrated precise agreement of the absorption cross-sections for the dilaton, and here we extend the result to Ramond-Ramond scalars and to gravitons polarized parallel to the brane. In string theory, the only absorption channel available to dilatons and Ramond-Ramond scalars at leading order is conversion into a pair of gauge bosons on the threebrane. For gravitons polarized parallel to the brane, scalars, fermions and gauge bosons all make leading order contributions to the cross-section, which remarkably add up to the value predicted by classical gravity. For the twobrane and fivebrane of M-theory, numerical coefficients fail to agree, signalling our lack of a precise understanding of the world-volume theory for large numbers of coincident branes. In many cases, we note a remarkable isotropy in the final state particle flux within the brane. We also consider the generalization to higher partial waves of minimally coupled scalars. We demonstrate agreement for the threebrane at l=1 and indicate that further work is necessary to understand l>1.
Hunter Fraser - One of the best experts on this subject based on the ideXlab platform.
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Identification and discussion of selected Roman objects. In: Cook, Martin, Lawson, John A and McLaren, Dawn, 'Excavations and Interventions in and around Cramond Roman Fort and Annexe, 1976 to 1990'. Scottish Archaeology Internet Report 74
The Society of Antiquaries of Scotland, 2017Co-Authors: Mclaren Dawn, Hunter FraserAbstract:Cramond Roman Fort has been the focus of archaeological interest since the publication of John Wood’s history of the parish in the late 18th century, with a floruit of activity in the latter half of the 20th century. Playing an important part in this volume of work have been the excavations led by the late Mr Charlie Hoy (d 1991), an Edinburgh amateur archaeologist working principally with the Edinburgh Archaeological Field Society and latterly on his own. His excavations have recovered a wide range of evidence from the Mesolithic through the Roman and medieval periods up to the post-medieval development of Cramond House Estate. Hoy’s investigations have been hugely important to our understanding of the Roman fort’s associated annexe/extramural settlement, in particular providing new evidence for its origins in the Antonine period, and for Severan occupation, as well as uncovering a multi-phased road and associated wooden structures. In addition, the artefact assemblage further adds to the corpus from the site and includes an internationally significant sword pendant belonging to a beneficiarius (beneficiarii were troops on special service for the provincial governor) that demonstrates the presence of German troops at the fort, and perhaps hints at the presence of the emperor himself
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The shale bangle fragments. In: Cook, Martin, Lawson, John A and McLaren, Dawn, 'Excavations and Interventions in and around Cramond Roman Fort and Annexe, 1976 to 1990'. Scottish Archaeology Internet Report 74
The Society of Antiquaries of Scotland, 2017Co-Authors: Hunter FraserAbstract:Cramond Roman Fort has been the focus of archaeological interest since the publication of John Wood’s history of the parish in the late 18th century, with a floruit of activity in the latter half of the 20th century. Playing an important part in this volume of work have been the excavations led by the late Mr Charlie Hoy (d 1991), an Edinburgh amateur archaeologist working principally with the Edinburgh Archaeological Field Society and latterly on his own. His excavations have recovered a wide range of evidence from the Mesolithic through the Roman and medieval periods up to the post-medieval development of Cramond House Estate. Hoy’s investigations have been hugely important to our understanding of the Roman fort’s associated annexe/extramural settlement, in particular providing new evidence for its origins in the Antonine period, and for Severan occupation, as well as uncovering a multi-phased road and associated wooden structures. In addition, the artefact assemblage further adds to the corpus from the site and includes an internationally significant sword pendant belonging to a beneficiarius (beneficiarii were troops on special service for the provincial governor) that demonstrates the presence of German troops at the fort, and perhaps hints at the presence of the emperor himself
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The Roman non-ferrous metal objects. In: Cook, Martin, Lawson, John A and McLaren, Dawn, 'Excavations and Interventions in and around Cramond Roman Fort and Annexe, 1976 to 1990'. Scottish Archaeology Internet Report 74
The Society of Antiquaries of Scotland, 2017Co-Authors: Hunter FraserAbstract:Cramond Roman Fort has been the focus of archaeological interest since the publication of John Wood’s history of the parish in the late 18th century, with a floruit of activity in the latter half of the 20th century. Playing an important part in this volume of work have been the excavations led by the late Mr Charlie Hoy (d 1991), an Edinburgh amateur archaeologist working principally with the Edinburgh Archaeological Field Society and latterly on his own. His excavations have recovered a wide range of evidence from the Mesolithic through the Roman and medieval periods up to the post-medieval development of Cramond House Estate. Hoy’s investigations have been hugely important to our understanding of the Roman fort’s associated annexe/extramural settlement, in particular providing new evidence for its origins in the Antonine period, and for Severan occupation, as well as uncovering a multi-phased road and associated wooden structures. In addition, the artefact assemblage further adds to the corpus from the site and includes an internationally significant sword pendant belonging to a beneficiarius (beneficiarii were troops on special service for the provincial governor) that demonstrates the presence of German troops at the fort, and perhaps hints at the presence of the emperor himself
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Copper alloy: Roman. In: Cook, Martin, Lawson, John A and McLaren, Dawn, 'Excavations and Interventions in and around Cramond Roman Fort and Annexe, 1976 to 1990'. Scottish Archaeology Internet Report 74
The Society of Antiquaries of Scotland, 2017Co-Authors: Hunter FraserAbstract:Cramond Roman Fort has been the focus of archaeological interest since the publication of John Wood’s history of the parish in the late 18th century, with a floruit of activity in the latter half of the 20th century. Playing an important part in this volume of work have been the excavations led by the late Mr Charlie Hoy (d 1991), an Edinburgh amateur archaeologist working principally with the Edinburgh Archaeological Field Society and latterly on his own. His excavations have recovered a wide range of evidence from the Mesolithic through the Roman and medieval periods up to the post-medieval development of Cramond House Estate. Hoy’s investigations have been hugely important to our understanding of the Roman fort’s associated annexe/extramural settlement, in particular providing new evidence for its origins in the Antonine period, and for Severan occupation, as well as uncovering a multi-phased road and associated wooden structures. In addition, the artefact assemblage further adds to the corpus from the site and includes an internationally significant sword pendant belonging to a beneficiarius (beneficiarii were troops on special service for the provincial governor) that demonstrates the presence of German troops at the fort, and perhaps hints at the presence of the emperor himself
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Tracing troops: an Upper German belt-fitting from Roman Scotland
The Society for the Promotion of Roman Studies, 2016Co-Authors: Hunter FraserAbstract:A silver belt-fitting from Cramond in the shape of a ring-pommel sword is linked to a class of beneficiarius equipment typical of Germania Superior. It is argued that this represents troop movements connected with the Severan campaigns
Rabin Banerjee - One of the best experts on this subject based on the ideXlab platform.
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anomalies in noncommutative gauge theories seiberg witten transformation and ramond ramond couplings
International Journal of Modern Physics A, 2004Co-Authors: Rabin BanerjeeAbstract:We propose an exact expression for the unintegrated form of the star gauge-invariant axial anomaly in an arbitrary even dimensional noncommutative gauge theory. The proposal is based on our earlier work,7 as well as on the inverse Seiberg–Witten map and identities related to it, obtained previously15,18 by comparing Ramond–Ramond couplings in different descriptions. The integrated anomalies, found from the unintegrated ones, are expressed in terms of a simplified version of the Elliott formula involving the noncommutative Chern character. These anomalies, under the Seiberg–Witten transformation, reduce to the ordinary (integrated) axial anomalies. Compatibility with existing results of anomalies in noncommutative theories is established.
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anomalies in noncommutative gauge theories seiberg witten transformation and ramond ramond couplings
arXiv: High Energy Physics - Theory, 2003Co-Authors: Rabin BanerjeeAbstract:We propose an exact expression for the unintegrated form of the star gauge invariant axial anomaly in an arbitrary even dimensional gauge theory. The proposal is based on the inverse Seiberg-Witten map and identities related to it, obtained earlier by comparing Ramond-Ramond couplings in different decsriptions. The integrated anomalies are expressed in terms of a simplified version of the Elliott formula involving the noncommutative Chern character. These anomalies, under the Seiberg-Witten transformation, reduce to the ordinary axial anomalies. Compatibility with existing results of anomalies in noncommutative theories is established.
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the translation groups as generators of gauge transformation in b f theory
Physics Letters B, 2001Co-Authors: Rabin Banerjee, Biswajit ChakrabortyAbstract:Abstract The translation group T (2), contained in Wigner's little group for massless particles, is shown to generate gauge transformations in the Kalb–Ramond theory, exactly as happens in Maxwell case. For the topologically massive (B∧F) gauge theory, both T (2) and T (3), act as the corresponding generators.
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the translation groups as generators of gauge transformation in b wedge f theory
arXiv: High Energy Physics - Theory, 2000Co-Authors: Rabin Banerjee, Biswajit ChakrabortyAbstract:The translation group T(2), contained in Wigner's little group for massless particles, is shown to generate gauge transformations in the Kalb-Ramond theory, exactly as happens in Maxwell case. For the topologically massive ($B\wedge$F) gauge theory, both T(2) and T(3), act as the corresponding generators.
Andrew Strominger - One of the best experts on this subject based on the ideXlab platform.
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massless black holes and conifolds in string theory
Nuclear Physics, 1995Co-Authors: Andrew StromingerAbstract:Abstract Low-energy effective field theories arising from Calabi-Yau string compactifications are generically inconsistent or ill-defined at the classical level because of conifold singularities in the moduli space. It is shown, given a plausible assumption on the degenaracies of black hole states, that for type II theories this inconsistency can be cured by nonperturbative quantum effects: the singularities are resolved by the appearance of massless Ramond-Ramond black holes. The Wilsonian effective action including these light black holes is smooth near the conifold, and the singularity is reproduced when they are integrated out. In order for a quantum effect to cure a classical inconsistency, it can not be suppressed by the usual string coupling g s . It is shown how the required g s dependence arises as a result of the peculiar couplings of Ramond-Ramond gauge fields to the dilaton.
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the heterotic string is a soliton
Nuclear Physics, 1995Co-Authors: J Harvey, Andrew StromingerAbstract:Abstract It is shown that the Type IIA superstring compactified on K 3 has a smooth string soliton with the same zero mode structure as the heterotic string compactified on a four-torus, thus providing new evidence for a conjectured exact duality between the two six-dimensional string theories. The chiral worldsheet bosons arise as zero modes of Ramond-Ramond fields of the IIA string theory and live on a signature (20,4) even, self-dual lattice. Stable, finite loops of soliton string provide the charged Ramond-Ramond states necessary for enhanced gauge symmetries at degeneration points of the K 3 surface. It is also shown that Type IIB strings toroidally compactified to six dimensions have a multiplet of string solutions with Type II worldsheets.
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massless black holes and conifolds in string theory
arXiv: High Energy Physics - Theory, 1995Co-Authors: Andrew StromingerAbstract:Low-energy effective field theories arising from Calabi-Yau string compactifications are generically inconsistent or ill-defined at the classical level because of conifold singularities in the moduli space. It is shown, given a plausible assumption on the degeneracies of black hole states, that for type II theories this inconsistency can be cured by nonperturbative quantum effects: the singularities are resolved by the appearance of massless Ramond-Ramond black holes. The Wilsonian effective action including these light black holes is smooth near the conifold, and the singularity is reproduced when they are integrated out. In order for a quantum effect to cure a classical inconsistency, it can not be suppressed by the usual string coupling $g_s$. It is shown how the required $g_s$ dependence arises as a result of the peculiar couplings of Ramond-Ramond gauge fields to the dilaton.
Hirosi Ooguri - One of the best experts on this subject based on the ideXlab platform.
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exact solution to the seiberg witten equation of noncommutative gauge theory
Physical Review D, 2001Co-Authors: Yuji Okawa, Hirosi OoguriAbstract:We derive an exact expression for the Seiberg-Witten map of noncommutative gauge theory. It is found by studying the coupling of the gauge field to the Ramond-Ramond potentials in string theory. Our result also proves the earlier conjecture by Liu.