George Papadopoulos | American Military University (original) (raw)

Papers by George Papadopoulos

Research paper thumbnail of Magnetic cosmic strings of supergravity with cosmological constant

Physics Letters B, 2001

We find a new class of cosmic string solutions with non-vanishing magnetic flux of N = 1, D = 4 s... more We find a new class of cosmic string solutions with non-vanishing magnetic flux of N = 1, D = 4 supergravity with a cosmological constant and coupled to any number of Maxwell and scalar multiplets. We show that these magnetic cosmic string solutions preserve 1/2 of supersymmetry. We give an explicit example of such a solution for which the complex scalars are constant and the spacetime is smooth with topology R 1,1 × S 2. Two more examples are explored for which a complex scalar field takes values in CP 1 and in SL(2, R)/U (1).

Research paper thumbnail of Compactification of D = 11 supergravity on spaces of exceptional holonomy

Physics Letters B, 1995

We investigate the compactification of D=11 supergravity to D=5,4,3, on compact manifolds of holo... more We investigate the compactification of D=11 supergravity to D=5,4,3, on compact manifolds of holonomy SU(3) (Calabi-Yau), G 2 , and Spin(7), respectively, making use of examples of the latter two cases found recently by Joyce. In each case the lower dimensional theory is a Maxwell/Einstein supergravity theory. We find evidence for an equivalence, in certain cases, with heterotic string compactifications from D=10 to D=5,4,3, on compact manifolds of holonomy SU(2) (K 3 ×S 1), SU(3), and G 2 , respectively. Calabi-Yau manifolds with Hodge numbers h 1,1 = h 1,2 = 19 play a significant role in the proposed equivalences.

Research paper thumbnail of Intersecting M-branes

Physics Letters B, 1996

We present the magnetic duals of Güven's electric-type solutions of D=11 supergravity preserving ... more We present the magnetic duals of Güven's electric-type solutions of D=11 supergravity preserving 1/4 or 1/8 of the D=11 supersymmetry. We interpret the electric solutions as n orthogonal intersecting membranes and the magnetic solutions as n orthogonal intersecting 5-branes, with n = 2, 3; these cases obey the general rule that p-branes can self-intersect on (p − 2)-branes. On reduction to D = 4 these solutions become electric or magnetic dilaton black holes with dilaton coupling constant a = 1 (for n = 2) or a = 1/ √ 3 (for n = 3). We also discuss the reduction to D=10.

Research paper thumbnail of Dynamical symmetry enhancement near IIA horizons

Journal of High Energy Physics, 2015

We show that smooth type IIA Killing horizons with compact spatial sections preserve an even numb... more We show that smooth type IIA Killing horizons with compact spatial sections preserve an even number of supersymmetries, and that the symmetry algebra of horizons with non-trivial fluxes includes an sl(2, R) subalgebra. This confirms the conjecture of [1] for type IIA horizons. As an intermediate step in the proof, we also demonstrate new Lichnerowicz type theorems for spin bundle connections whose holonomy is contained in a general linear group.

Research paper thumbnail of Brane potentials and moduli spaces

Journal of High Energy Physics, 2000

It is shown that the supergravity moduli spaces of D1-D5 and D2-D6 brane systems coincide with th... more It is shown that the supergravity moduli spaces of D1-D5 and D2-D6 brane systems coincide with those of the Coulomb branches of the associated non-abelian gauge theories. We further discuss situations in which worldvolume brane actions include a potential term generated by probing certain supergravity backgrounds. We find that in many cases, the appearance of the potential is due to the application of the Scherk-Schwarz mechanism. We give some examples and discuss the existence of novel supersymmetric brane configurations.

Research paper thumbnail of Dyonic p-branes from self-dual (p + 1)-branes

Physics Letters B, 1996

The 'electromagnetic' Sl(2; Z) duality group in spacetime dimension D = 4k can be given a Kaluza-... more The 'electromagnetic' Sl(2; Z) duality group in spacetime dimension D = 4k can be given a Kaluza-Klein interpretation in D = 4k + 2 as the modular group of a compactifying torus. We show how dyonic 2(k − 1)-branes in D = 4k can be interpreted as self-dual (2k − 1)-branes in D = 4k + 2 wound around the homology cycles of the torus. In particular, dyons of the D=4 N=4 heterotic string theory are interpreted as winding modes of a D=6 self-dual string, while D=8 dyonic membranes are interpreted as wound 3-branes of D=10 IIB superstring theory. We also discuss the T-dual IIA interpretations of D=8 dyonic membranes.

Research paper thumbnail of Domain walls on the brane

Physics Letters B, 1998

We show that all branes admit worldvolume domain wall solutions. We find one class of solutions f... more We show that all branes admit worldvolume domain wall solutions. We find one class of solutions for which the tension of the brane changes discontinuously along the domain wall. These solutions are not supersymmetric. We argue that there is another class of domain wall solutions which is supersymmetric. A particular case concerns supersymmetric domain wall solutions on IIB D-5-and NS-5-branes.

Research paper thumbnail of T-duality and the worldvolume solitons of five-branes and KK-monopoles

Physics Letters B, 1998

We show that the fluxes of the various six-dimensional "gauge" theories are associated to below t... more We show that the fluxes of the various six-dimensional "gauge" theories are associated to below threshold bound states of D-branes with the NS-5-branes and KK-monopoles which preserve half of bulk supersymmetry. We then present the supergravity solutions that correspond to these bound states. In addition using the worldvolume solitons of IIA and IIB NS-5-branes and KK-monopoles, we investigate the sectors of the "gauge" theories that preserve one quarter of bulk supersymmetry. This leads to a generalization a supergravity solution which has the interpretation of two intersecting NS-5-branes at a 3-brane and to the construction of some of the worldvolume solitons of IIA and M-theory KK-monopoles. Furthermore, using the IIA/IIB T-duality of the bulk theories, we give the T-duality transformations of the worldvolume solitons of NS-5-branes and KK-monopoles. We find that the worldvolume 0-brane, self-dual string and 2-brane solitons of NS-5-branes appear in the same T-duality chain.

Research paper thumbnail of Kaluza-Klein on the brane

Physics Letters B, 1997

The M-theory interpretation of certain D=10 IIA p-branes implies the existence of worldvolume Kal... more The M-theory interpretation of certain D=10 IIA p-branes implies the existence of worldvolume Kaluza-Klein modes which are expected to appear as 0-brane/pbrane bound states preserving 1/4 of the spacetime supersymmetry. We construct the corresponding solutions of the effective supergravity theory for p = 1, 4, and show that no such solution exists for p = 8.

Research paper thumbnail of Supersymmetry and generalized calibrations

Physical Review D, 1999

A static minimal energy configuration of a super p-brane in a supersymmetric (n+1)-dimensional sp... more A static minimal energy configuration of a super p-brane in a supersymmetric (n+1)-dimensional spacetime is shown to be a 'generalized calibrated' submanifold. Calibrations in E (1,n) and AdSn+1 are special cases. We present several M-brane examples. * The requirement that ǫ be real restricts the spacetime dimension, and hence the space dimension n; the extent to which the constraints on p and n may be relaxed will be discussed below.

Research paper thumbnail of Dyonic membranes

Nuclear Physics B, 1996

We present dyonic multi-membrane solutions of the N=2 D=8 supergravity theory that serves as the ... more We present dyonic multi-membrane solutions of the N=2 D=8 supergravity theory that serves as the effective field theory of the T 2-compactified type II superstring theory. The 'electric' charge is fractional for generic asymptotic values of an axion field, as for D=4 dyons. These membrane solutions are supersymmetric, saturate a Bogomolnyi bound, fill out orbits of an Sl(2; Z) subgroup of the type II D=8 T-duality group, and are non-singular when considered as solutions of T 3-compactified D=11 supergravity. On K 3 compactification to D=4, the conjectured type II/heterotic equivalence allows the Sl(2; Z) group to be reinterpreted as the S-duality group of the toroidally compactified heterotic string and the dyonic membranes wrapped around homology two-cycles of K 3 as S-duals of perturbative heterotic string states.

Research paper thumbnail of HKT and OKT geometries on soliton black hole moduli spaces

Nuclear Physics B, 1997

We consider Shiraishi's metrics on the moduli space of extreme black holes. We interpret the simp... more We consider Shiraishi's metrics on the moduli space of extreme black holes. We interpret the simplification in the pattern of N-body interactions that he observed in terms of the recent picture of black holes in four and five dimensions as composites, made up of intersecting branes. We then show that the geometry of the moduli space of a class of black holes in five and nine dimensions is hyper-Kähler with torsion, and octonionic-Kähler with torsion, respectively. For this, we examine the geometry of point particle models with extended world-line supersymmetry and show that both of the above geometries arise naturally in this context. In addition, we construct a large class of hyper-Kähler with torsion and octonionic-Kähler with torsion geometries in various dimensions. We also present a brane interpretation of our results.

Research paper thumbnail of Hyper-Kähler manifolds and multiply intersecting branes

Nuclear Physics B, 1997

Generalized membrane solutions of D=11 supergravity, for which the transverse space is a toric hy... more Generalized membrane solutions of D=11 supergravity, for which the transverse space is a toric hyper-K ahler manifold, are shown to have IIB duals representing the intersection of parallel 3-branes with 5-branes whose orientations are determined by their Sl(2; Z) charge vectors. These IIB solutions, which generically preserve 3/16 of the supersymmetry, can be further mapped to solutions of D=11 supergravity representing the intersection of parallel membranes with any number of fivebranes at arbitrary angles. Alternatively, a subclass (corresponding to nonsingular D=11 solutions) can be mapped to solutions representing the intersection on a string of any number of D-5-branes at arbitrary angles, again preserving 3/16 supersymmetry, as we verify in a special case by a quaternionic extension of the analysis of Berkooz, Douglas and Leigh. We also use similar methods to find new 1/8 supersymmetric solutions of orthogonally intersecting branes.

Research paper thumbnail of The dynamics of D3-brane dyons and toric hyper-Kähler manifold

Nuclear Physics B, 1999

We find the dyonic worldvolume solitons due to parallel (p,q) strings ending on a D-3-brane. Thes... more We find the dyonic worldvolume solitons due to parallel (p,q) strings ending on a D-3-brane. These solutions preserve 1/4 of bulk supersymmetry. Then we investigate the scattering of well-separated dyons and find that their moduli space is a toric hyper-Kähler manifold. In addition, we present the worldvolume solitons of the D-3-brane which are related by duality to the M-theory configuration of two orthogonal membranes ending on a M-5-brane. We show that these solitons preserve 1/8 of supersymmetry and compute their effective action.

Research paper thumbnail of The IIA super-eightbrane

We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which ... more We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which the field equations are equivalent to those of the standard, massless, IIA theory for vanishing 10-form field strength, F10F_{10}F10, and to those of the `massive' IIA theory for non-vanishing F10F_{10}F10. We exhibit a multi 8-brane solution of this theory which preserves half the supersymmetry. We propose this solution as the effective field theory realization of the Dirichlet 8-brane of type IIA superstring theory.

Research paper thumbnail of Calibrations and Intersecting Branes

Communications in Mathematical Physics, 1999

We investigate the solutions of Nambu-Goto-type actions associated with calibrations. We determin... more We investigate the solutions of Nambu-Goto-type actions associated with calibrations. We determine the supersymmetry preserved by these solutions using the contact set of the calibration and examine their bulk interpretation as intersecting branes. We show that the supersymmetry preserved by such solutions is closely related to the spinor singlets of the subgroup G of Spin(9, 1) or Spin(10, 1) that rotates the tangent spaces of the brane. We find that the supersymmetry projections of the worldvolume solutions are precisely those of the associated bulk configurations. We also investigate the supersymmetric solutions of a Born-Infeld action. We show that in some cases this problem also reduces to counting spinor singlets of a subgroup of Spin(9, 1) acting on the associated spinor representations. We also find new worldvolume solutions which preserve 1/8 of the supersymmetry of the bulk and give their bulk interpretation.

Research paper thumbnail of Instantons at angles

Physics Letters B, 1998

We interpret a class of 4k-dimensional instanton solutions found by Ward, Corrigan, Goddard and K... more We interpret a class of 4k-dimensional instanton solutions found by Ward, Corrigan, Goddard and Kent as four-dimensional instantons at angles. The superposition of each pair of four-dimensional instantons is associated with four angles which depend on some of the ADHM parameters. All these solutions are associated with the group Sp(k) and are examples of Hermitian-Einstein connections on E 4k. We show that the eight-dimensional solutions preserve 3/16 of the ten-dimensional N=1 supersymmetry. We argue that under the correspondence between the BPS states of Yang-Mills theory and those of M-theory that arises in the context of Matrix models, the instantons at angles configuration corresponds to the longitudinal intersecting 5-branes on a string at angles configuration of M-theory.

Research paper thumbnail of A model for prediction of desert dust cycle in the atmosphere

Journal of Geophysical Research, Jan 1, 2001

Page 1. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 106, NO. D16, PAGES 18,113-18,129, AUGUST 27, 2001 ... more Page 1. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 106, NO. D16, PAGES 18,113-18,129, AUGUST 27, 2001 A model for prediction of desert dust cycle in the atmosphere Slobodan Nickovic Euro-Mediterranean Centre ...

Research paper thumbnail of Duality of type-II 7-branes and 8-branes

Nuclear Physics B, Jan 1, 1996

We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which ... more We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which the field equations are equivalent to those of the standard, massless, IIA theory for vanishing 10-form field strength, F10, and to those of the ‘massive’ IIA theory for non-vanishing F10. We present a multi 8-brane solution of these equations that generalizes the 8-brane of Polchinski and Witten. We show that this solution is T-dual to a new multi 7-brane solution of S1 compactified IIIB supergravity, and that the latter is T-dual to the IIA 6-brane. When combined with the ) U-duality of the type-IIB superstring, the T-duality between type-11 7-branes and 8-branes implies a quantization of the cosmological constant of type-IIA superstring theory. These results are made possible by the construction of a new massiveN = 2 D = 9 supergravity theory. We also discuss the 11-dimensional interpretation of these type-II p-branes.

Research paper thumbnail of The CMS Collaboration

Nuclear Physics A, Jan 1, 2009

, A and Heinrich, M and Heister, A and Heltsley, B and Hermanns, T and Hernandez, JM and Herquet,... more , A and Heinrich, M and Heister, A and Heltsley, B and Hermanns, T and Hernandez, JM and Herquet, P and Hervé, A and Heyburn, B and Heydhausen, D and Hildreth, M and Hill, C and Hintz, W and Hinzmann, A and Hirosky, R and Hits, D and Hobson, PR and Hoch, M and Hoepfner, K and Hoermann, N and Hof, C and Hoffmann, KH and Hoffmann, HF and Hofman, DJ and Hohlmann, M and Hollar, J and Hollingsworth, M and Holmes, D and Holzner, A and Honc, S and Hong, BS and Honma, A and Hoorani, HR and Hopkins, W ...

Research paper thumbnail of Magnetic cosmic strings of supergravity with cosmological constant

Physics Letters B, 2001

We find a new class of cosmic string solutions with non-vanishing magnetic flux of N = 1, D = 4 s... more We find a new class of cosmic string solutions with non-vanishing magnetic flux of N = 1, D = 4 supergravity with a cosmological constant and coupled to any number of Maxwell and scalar multiplets. We show that these magnetic cosmic string solutions preserve 1/2 of supersymmetry. We give an explicit example of such a solution for which the complex scalars are constant and the spacetime is smooth with topology R 1,1 × S 2. Two more examples are explored for which a complex scalar field takes values in CP 1 and in SL(2, R)/U (1).

Research paper thumbnail of Compactification of D = 11 supergravity on spaces of exceptional holonomy

Physics Letters B, 1995

We investigate the compactification of D=11 supergravity to D=5,4,3, on compact manifolds of holo... more We investigate the compactification of D=11 supergravity to D=5,4,3, on compact manifolds of holonomy SU(3) (Calabi-Yau), G 2 , and Spin(7), respectively, making use of examples of the latter two cases found recently by Joyce. In each case the lower dimensional theory is a Maxwell/Einstein supergravity theory. We find evidence for an equivalence, in certain cases, with heterotic string compactifications from D=10 to D=5,4,3, on compact manifolds of holonomy SU(2) (K 3 ×S 1), SU(3), and G 2 , respectively. Calabi-Yau manifolds with Hodge numbers h 1,1 = h 1,2 = 19 play a significant role in the proposed equivalences.

Research paper thumbnail of Intersecting M-branes

Physics Letters B, 1996

We present the magnetic duals of Güven's electric-type solutions of D=11 supergravity preserving ... more We present the magnetic duals of Güven's electric-type solutions of D=11 supergravity preserving 1/4 or 1/8 of the D=11 supersymmetry. We interpret the electric solutions as n orthogonal intersecting membranes and the magnetic solutions as n orthogonal intersecting 5-branes, with n = 2, 3; these cases obey the general rule that p-branes can self-intersect on (p − 2)-branes. On reduction to D = 4 these solutions become electric or magnetic dilaton black holes with dilaton coupling constant a = 1 (for n = 2) or a = 1/ √ 3 (for n = 3). We also discuss the reduction to D=10.

Research paper thumbnail of Dynamical symmetry enhancement near IIA horizons

Journal of High Energy Physics, 2015

We show that smooth type IIA Killing horizons with compact spatial sections preserve an even numb... more We show that smooth type IIA Killing horizons with compact spatial sections preserve an even number of supersymmetries, and that the symmetry algebra of horizons with non-trivial fluxes includes an sl(2, R) subalgebra. This confirms the conjecture of [1] for type IIA horizons. As an intermediate step in the proof, we also demonstrate new Lichnerowicz type theorems for spin bundle connections whose holonomy is contained in a general linear group.

Research paper thumbnail of Brane potentials and moduli spaces

Journal of High Energy Physics, 2000

It is shown that the supergravity moduli spaces of D1-D5 and D2-D6 brane systems coincide with th... more It is shown that the supergravity moduli spaces of D1-D5 and D2-D6 brane systems coincide with those of the Coulomb branches of the associated non-abelian gauge theories. We further discuss situations in which worldvolume brane actions include a potential term generated by probing certain supergravity backgrounds. We find that in many cases, the appearance of the potential is due to the application of the Scherk-Schwarz mechanism. We give some examples and discuss the existence of novel supersymmetric brane configurations.

Research paper thumbnail of Dyonic p-branes from self-dual (p + 1)-branes

Physics Letters B, 1996

The 'electromagnetic' Sl(2; Z) duality group in spacetime dimension D = 4k can be given a Kaluza-... more The 'electromagnetic' Sl(2; Z) duality group in spacetime dimension D = 4k can be given a Kaluza-Klein interpretation in D = 4k + 2 as the modular group of a compactifying torus. We show how dyonic 2(k − 1)-branes in D = 4k can be interpreted as self-dual (2k − 1)-branes in D = 4k + 2 wound around the homology cycles of the torus. In particular, dyons of the D=4 N=4 heterotic string theory are interpreted as winding modes of a D=6 self-dual string, while D=8 dyonic membranes are interpreted as wound 3-branes of D=10 IIB superstring theory. We also discuss the T-dual IIA interpretations of D=8 dyonic membranes.

Research paper thumbnail of Domain walls on the brane

Physics Letters B, 1998

We show that all branes admit worldvolume domain wall solutions. We find one class of solutions f... more We show that all branes admit worldvolume domain wall solutions. We find one class of solutions for which the tension of the brane changes discontinuously along the domain wall. These solutions are not supersymmetric. We argue that there is another class of domain wall solutions which is supersymmetric. A particular case concerns supersymmetric domain wall solutions on IIB D-5-and NS-5-branes.

Research paper thumbnail of T-duality and the worldvolume solitons of five-branes and KK-monopoles

Physics Letters B, 1998

We show that the fluxes of the various six-dimensional "gauge" theories are associated to below t... more We show that the fluxes of the various six-dimensional "gauge" theories are associated to below threshold bound states of D-branes with the NS-5-branes and KK-monopoles which preserve half of bulk supersymmetry. We then present the supergravity solutions that correspond to these bound states. In addition using the worldvolume solitons of IIA and IIB NS-5-branes and KK-monopoles, we investigate the sectors of the "gauge" theories that preserve one quarter of bulk supersymmetry. This leads to a generalization a supergravity solution which has the interpretation of two intersecting NS-5-branes at a 3-brane and to the construction of some of the worldvolume solitons of IIA and M-theory KK-monopoles. Furthermore, using the IIA/IIB T-duality of the bulk theories, we give the T-duality transformations of the worldvolume solitons of NS-5-branes and KK-monopoles. We find that the worldvolume 0-brane, self-dual string and 2-brane solitons of NS-5-branes appear in the same T-duality chain.

Research paper thumbnail of Kaluza-Klein on the brane

Physics Letters B, 1997

The M-theory interpretation of certain D=10 IIA p-branes implies the existence of worldvolume Kal... more The M-theory interpretation of certain D=10 IIA p-branes implies the existence of worldvolume Kaluza-Klein modes which are expected to appear as 0-brane/pbrane bound states preserving 1/4 of the spacetime supersymmetry. We construct the corresponding solutions of the effective supergravity theory for p = 1, 4, and show that no such solution exists for p = 8.

Research paper thumbnail of Supersymmetry and generalized calibrations

Physical Review D, 1999

A static minimal energy configuration of a super p-brane in a supersymmetric (n+1)-dimensional sp... more A static minimal energy configuration of a super p-brane in a supersymmetric (n+1)-dimensional spacetime is shown to be a 'generalized calibrated' submanifold. Calibrations in E (1,n) and AdSn+1 are special cases. We present several M-brane examples. * The requirement that ǫ be real restricts the spacetime dimension, and hence the space dimension n; the extent to which the constraints on p and n may be relaxed will be discussed below.

Research paper thumbnail of Dyonic membranes

Nuclear Physics B, 1996

We present dyonic multi-membrane solutions of the N=2 D=8 supergravity theory that serves as the ... more We present dyonic multi-membrane solutions of the N=2 D=8 supergravity theory that serves as the effective field theory of the T 2-compactified type II superstring theory. The 'electric' charge is fractional for generic asymptotic values of an axion field, as for D=4 dyons. These membrane solutions are supersymmetric, saturate a Bogomolnyi bound, fill out orbits of an Sl(2; Z) subgroup of the type II D=8 T-duality group, and are non-singular when considered as solutions of T 3-compactified D=11 supergravity. On K 3 compactification to D=4, the conjectured type II/heterotic equivalence allows the Sl(2; Z) group to be reinterpreted as the S-duality group of the toroidally compactified heterotic string and the dyonic membranes wrapped around homology two-cycles of K 3 as S-duals of perturbative heterotic string states.

Research paper thumbnail of HKT and OKT geometries on soliton black hole moduli spaces

Nuclear Physics B, 1997

We consider Shiraishi's metrics on the moduli space of extreme black holes. We interpret the simp... more We consider Shiraishi's metrics on the moduli space of extreme black holes. We interpret the simplification in the pattern of N-body interactions that he observed in terms of the recent picture of black holes in four and five dimensions as composites, made up of intersecting branes. We then show that the geometry of the moduli space of a class of black holes in five and nine dimensions is hyper-Kähler with torsion, and octonionic-Kähler with torsion, respectively. For this, we examine the geometry of point particle models with extended world-line supersymmetry and show that both of the above geometries arise naturally in this context. In addition, we construct a large class of hyper-Kähler with torsion and octonionic-Kähler with torsion geometries in various dimensions. We also present a brane interpretation of our results.

Research paper thumbnail of Hyper-Kähler manifolds and multiply intersecting branes

Nuclear Physics B, 1997

Generalized membrane solutions of D=11 supergravity, for which the transverse space is a toric hy... more Generalized membrane solutions of D=11 supergravity, for which the transverse space is a toric hyper-K ahler manifold, are shown to have IIB duals representing the intersection of parallel 3-branes with 5-branes whose orientations are determined by their Sl(2; Z) charge vectors. These IIB solutions, which generically preserve 3/16 of the supersymmetry, can be further mapped to solutions of D=11 supergravity representing the intersection of parallel membranes with any number of fivebranes at arbitrary angles. Alternatively, a subclass (corresponding to nonsingular D=11 solutions) can be mapped to solutions representing the intersection on a string of any number of D-5-branes at arbitrary angles, again preserving 3/16 supersymmetry, as we verify in a special case by a quaternionic extension of the analysis of Berkooz, Douglas and Leigh. We also use similar methods to find new 1/8 supersymmetric solutions of orthogonally intersecting branes.

Research paper thumbnail of The dynamics of D3-brane dyons and toric hyper-Kähler manifold

Nuclear Physics B, 1999

We find the dyonic worldvolume solitons due to parallel (p,q) strings ending on a D-3-brane. Thes... more We find the dyonic worldvolume solitons due to parallel (p,q) strings ending on a D-3-brane. These solutions preserve 1/4 of bulk supersymmetry. Then we investigate the scattering of well-separated dyons and find that their moduli space is a toric hyper-Kähler manifold. In addition, we present the worldvolume solitons of the D-3-brane which are related by duality to the M-theory configuration of two orthogonal membranes ending on a M-5-brane. We show that these solitons preserve 1/8 of supersymmetry and compute their effective action.

Research paper thumbnail of The IIA super-eightbrane

We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which ... more We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which the field equations are equivalent to those of the standard, massless, IIA theory for vanishing 10-form field strength, F10F_{10}F10, and to those of the `massive' IIA theory for non-vanishing F10F_{10}F10. We exhibit a multi 8-brane solution of this theory which preserves half the supersymmetry. We propose this solution as the effective field theory realization of the Dirichlet 8-brane of type IIA superstring theory.

Research paper thumbnail of Calibrations and Intersecting Branes

Communications in Mathematical Physics, 1999

We investigate the solutions of Nambu-Goto-type actions associated with calibrations. We determin... more We investigate the solutions of Nambu-Goto-type actions associated with calibrations. We determine the supersymmetry preserved by these solutions using the contact set of the calibration and examine their bulk interpretation as intersecting branes. We show that the supersymmetry preserved by such solutions is closely related to the spinor singlets of the subgroup G of Spin(9, 1) or Spin(10, 1) that rotates the tangent spaces of the brane. We find that the supersymmetry projections of the worldvolume solutions are precisely those of the associated bulk configurations. We also investigate the supersymmetric solutions of a Born-Infeld action. We show that in some cases this problem also reduces to counting spinor singlets of a subgroup of Spin(9, 1) acting on the associated spinor representations. We also find new worldvolume solutions which preserve 1/8 of the supersymmetry of the bulk and give their bulk interpretation.

Research paper thumbnail of Instantons at angles

Physics Letters B, 1998

We interpret a class of 4k-dimensional instanton solutions found by Ward, Corrigan, Goddard and K... more We interpret a class of 4k-dimensional instanton solutions found by Ward, Corrigan, Goddard and Kent as four-dimensional instantons at angles. The superposition of each pair of four-dimensional instantons is associated with four angles which depend on some of the ADHM parameters. All these solutions are associated with the group Sp(k) and are examples of Hermitian-Einstein connections on E 4k. We show that the eight-dimensional solutions preserve 3/16 of the ten-dimensional N=1 supersymmetry. We argue that under the correspondence between the BPS states of Yang-Mills theory and those of M-theory that arises in the context of Matrix models, the instantons at angles configuration corresponds to the longitudinal intersecting 5-branes on a string at angles configuration of M-theory.

Research paper thumbnail of A model for prediction of desert dust cycle in the atmosphere

Journal of Geophysical Research, Jan 1, 2001

Page 1. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 106, NO. D16, PAGES 18,113-18,129, AUGUST 27, 2001 ... more Page 1. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 106, NO. D16, PAGES 18,113-18,129, AUGUST 27, 2001 A model for prediction of desert dust cycle in the atmosphere Slobodan Nickovic Euro-Mediterranean Centre ...

Research paper thumbnail of Duality of type-II 7-branes and 8-branes

Nuclear Physics B, Jan 1, 1996

We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which ... more We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which the field equations are equivalent to those of the standard, massless, IIA theory for vanishing 10-form field strength, F10, and to those of the ‘massive’ IIA theory for non-vanishing F10. We present a multi 8-brane solution of these equations that generalizes the 8-brane of Polchinski and Witten. We show that this solution is T-dual to a new multi 7-brane solution of S1 compactified IIIB supergravity, and that the latter is T-dual to the IIA 6-brane. When combined with the ) U-duality of the type-IIB superstring, the T-duality between type-11 7-branes and 8-branes implies a quantization of the cosmological constant of type-IIA superstring theory. These results are made possible by the construction of a new massiveN = 2 D = 9 supergravity theory. We also discuss the 11-dimensional interpretation of these type-II p-branes.

Research paper thumbnail of The CMS Collaboration

Nuclear Physics A, Jan 1, 2009

, A and Heinrich, M and Heister, A and Heltsley, B and Hermanns, T and Hernandez, JM and Herquet,... more , A and Heinrich, M and Heister, A and Heltsley, B and Hermanns, T and Hernandez, JM and Herquet, P and Hervé, A and Heyburn, B and Heydhausen, D and Hildreth, M and Hill, C and Hintz, W and Hinzmann, A and Hirosky, R and Hits, D and Hobson, PR and Hoch, M and Hoepfner, K and Hoermann, N and Hof, C and Hoffmann, KH and Hoffmann, HF and Hofman, DJ and Hohlmann, M and Hollar, J and Hollingsworth, M and Holmes, D and Holzner, A and Honc, S and Hong, BS and Honma, A and Hoorani, HR and Hopkins, W ...