%0 Report %D 2020 %T On the gauge group of Galois objects %A Xiao Han %A Giovanni Landi %X We study the Ehresmann--Schauenburg bialgebroid of a noncommutative principal bundle as a quantization of the classical gauge groupoid of a principal bundle. When the base algebra is in the centre of the total space algebra, the gauge group of the noncommutative principal bundle is isomorphic to the group of bisections of the bialgebroid. In particular we consider Galois objects (non-trivial noncommutative bundles over a point in a sense) for which the bialgebroid is a Hopf algebra. For these we give a crossed module structure for the bisections and the automorphisms of the bialgebroid. Examples include Galois objects of group Hopf algebras and of Taft algebras. %8 03/2020 %G eng %U https://arxiv.org/abs/2002.06097 %0 Journal Article %J Reviews in Mathematical Physics %D 2018 %T Principal fibrations over noncommutative spheres %A Michel Dubois-Violette %A Xiao Han %A Giovanni Landi %X We present examples of noncommutative four-spheres that are base spaces of $SU(2)$-principal bundles with noncommutative seven-spheres as total spaces. The noncommutative coordinate algebras of the four-spheres are generated by the entries of a projection which is invariant under the action of $SU(2)$. We give conditions for the components of the Connes–Chern character of the projection to vanish but the second (the top) one. The latter is then a non-zero Hochschild cycle that plays the role of the volume form for the noncommutative four-spheres. %B Reviews in Mathematical Physics %V 30 %P 1850020 %G eng %U https://arxiv.org/abs/1804.07032 %R 10.1142/S0129055X18500204 %0 Journal Article %J Journal of Noncommutative Geometry %D 2016 %T The Gysin sequence for quantum lens spaces %A Francesca Arici %A Simon Brain %A Giovanni Landi %X

We define quantum lens spaces as ‘direct sums of line bundles’ and exhibit them as ‘total spaces’ of certain principal bundles over quantum projective spaces. For each of these quantum lens spaces we construct an analogue of the classical Gysin sequence in K-theory. We use the sequence to compute the K-theory of the quantum lens spaces, in particular to give explicit geometric representatives of their K-theory classes. These representatives are interpreted as ‘line bundles’ over quantum lens spaces and generically define ‘torsion classes’. We work out explicit examples of these classes.

%B Journal of Noncommutative Geometry %V 9 %P 1077–1111 %G eng %R 10.4171/JNCG/216 %0 Book Section %B Noncommutative Analysis, Operator Theory and Applications %D 2016 %T Pimsner Algebras and Circle Bundles %A Francesca Arici %A Francesco D'Andrea %A Giovanni Landi %E Alpay, Daniel %E Cipriani, Fabio %E Colombo, Fabrizio %E Guido, Daniele %E Sabadini, Irene %E Sauvageot, Jean-Luc %X

We report on the connections between noncommutative principal circle bundles, Pimsner algebras and strongly graded algebras. We illustrate several results with examples of quantum weighted projective and lens spaces and θ-deformations.

%B Noncommutative Analysis, Operator Theory and Applications %I Springer International Publishing %C Cham %P 1–25 %@ 978-3-319-29116-1 %G eng %U https://doi.org/10.1007/978-3-319-29116-1_1 %R 10.1007/978-3-319-29116-1_1 %0 Journal Article %J Journal of Noncommutative Geometry %D 2016 %T Pimsner algebras and Gysin sequences from principal circle actions %A Francesca Arici %A Jens Kaad %A Giovanni Landi %B Journal of Noncommutative Geometry %V 10 %P 29–64 %G eng %U http://hdl.handle.net/2066/162951 %R 10.4171/jncg/228 %0 Journal Article %J Quarterly Journal of Mathematics (2012) 63 (1): 41-86 %D 2012 %T Moduli spaces of noncommutative instantons: gauging away noncommutative parameters %A Simon Brain %A Giovanni Landi %X Using the theory of noncommutative geometry in a braided monoidal category, we improve upon a previous construction of noncommutative families of instantons of arbitrary charge on the deformed sphere S^4_\\\\theta. We formulate a notion of noncommutative parameter spaces for families of instantons and we explore what it means for such families to be gauge equivalent, as well as showing how to remove gauge parameters using a noncommutative quotient construction. Although the parameter spaces are a priori noncommutative, we show that one may always recover a classical parameter space by making an appropriate choice of gauge transformation. %B Quarterly Journal of Mathematics (2012) 63 (1): 41-86 %I Oxford University Press %G en_US %U http://hdl.handle.net/1963/3777 %1 548 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2009-10-26T14:39:30Z\\r\\nNo. of bitstreams: 1\\r\\n0909.4402.pdf: 469021 bytes, checksum: bbcda76215b8bb90a5704b81326e9dde (MD5) %R 10.1093/qmath/haq036 %0 Report %D 2009 %T Families of Monads and Instantons from a Noncommutative ADHM Construction %A Simon Brain %A Giovanni Landi %X We give a \\\\theta-deformed version of the ADHM construction of SU(2) instantons with arbitrary topological charge on the sphere S^4. Classically the instanton gauge fields are constructed from suitable monad data; we show that in the deformed case the set of monads is itself a noncommutative space. We use these monads to construct noncommutative `families\\\' of SU(2) instantons on the deformed sphere S^4_\\\\theta. We also compute the topological charge of each of the families. Finally we discuss what it means for such families to be gauge equivalent. %G en_US %U http://hdl.handle.net/1963/3478 %1 786 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2009-02-03T16:03:42Z\\nNo. of bitstreams: 1\\nBrain_Landi.pdf: 343656 bytes, checksum: 7d0ea754b63fce4b2a83db6423e67650 (MD5) %0 Journal Article %J Comm. Math. Phys. 287 (2009) 179-209 %D 2009 %T Gauged Laplacians on quantum Hopf bundles %A Giovanni Landi %A Cesare Reina %A Alessandro Zampini %X We study gauged Laplacian operators on line bundles on a quantum 2-dimensional sphere. Symmetry under the (co)-action of a quantum group allows for their complete diagonalization. These operators describe `excitations moving on the quantum sphere\\\' in the field of a magnetic monopole. The energies are not invariant under the exchange monopole/antimonopole, that is under inverting the direction of the magnetic field. There are potential applications to models of quantum Hall effect. %B Comm. Math. Phys. 287 (2009) 179-209 %I Springer %G en_US %U http://hdl.handle.net/1963/3540 %1 1161 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2009-02-24T09:35:24Z\\nNo. of bitstreams: 1\\n0801.3376v2.pdf: 353792 bytes, checksum: 1153ca993428f38ef95f7d31cd727743 (MD5) %R 10.1007/s00220-008-0672-5 %0 Journal Article %J Comm. Math. Phys. 279 (2008) 77-116 %D 2008 %T The Isospectral Dirac Operator on the 4-dimensional Orthogonal Quantum Sphere %A Francesco D'Andrea %A Ludwik Dabrowski %A Giovanni Landi %X Equivariance under the action of Uq(so(5)) is used to compute the left regular and (chiral) spinorial representations of the algebra of the quantum Euclidean 4-sphere S^4_q. These representations are the constituents of a spectral triple on this sphere with a Dirac operator which is isospectral to the canonical one of the spin structure of the round undeformed four-sphere and which gives metric dimension four for the noncommutative geometry. Non-triviality of the geometry is proved by pairing the associated Fredholm module with an `instanton\\\' projection. A real structure which satisfies all required properties modulo a suitable ideal of `infinitesimals\\\' is also introduced. %B Comm. Math. Phys. 279 (2008) 77-116 %G en_US %U http://hdl.handle.net/1963/2567 %1 1553 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2008-01-18T11:00:40Z\\nNo. of bitstreams: 1\\n0611100v1.pdf: 351975 bytes, checksum: 8dd0f817683bd7782e5110ca6b585b91 (MD5) %R 10.1007/s00220-008-0420-x %0 Journal Article %J Int. Math. Res. Not. vol. 2008, Article ID rnn038 %D 2008 %T Noncommutative families of instantons %A Giovanni Landi %A Chiara Pagani %A Cesare Reina %A Walter van Suijlekom %X We construct $\\\\theta$-deformations of the classical groups SL(2,H) and Sp(2). Coacting on the basic instanton on a noncommutative four-sphere $S^4_\\\\theta$, we construct a noncommutative family of instantons of charge 1. The family is parametrized by the quantum quotient of $SL_\\\\theta(2,H)$ by $Sp_\\\\theta(2)$. %B Int. Math. Res. Not. vol. 2008, Article ID rnn038 %I Oxford University Press %G en_US %U http://hdl.handle.net/1963/3417 %1 918 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2009-01-12T09:40:47Z\\nNo. of bitstreams: 1\\n0710.0721v2.pdf: 290960 bytes, checksum: 7203f1e1dd34fd90d8d3201c7b813b44 (MD5) %R 10.1093/imrn/rnn038 %0 Journal Article %J Rev. Math. Phys. 20 (2008) 979-1006 %D 2008 %T The Noncommutative Geometry of the Quantum Projective Plane %A Francesco D'Andrea %A Ludwik Dabrowski %A Giovanni Landi %X We study the spectral geometry of the quantum projective plane CP^2_q. In particular, we construct a Dirac operator which gives a 0^+ summable triple, equivariant under U_q(su(3)). %B Rev. Math. Phys. 20 (2008) 979-1006 %G en_US %U http://hdl.handle.net/1963/2548 %1 1571 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2008-01-14T08:17:29Z\\nNo. of bitstreams: 1\\n0712.3401v1.pdf: 305773 bytes, checksum: 85ef21e8ac9485f12064685740331fc2 (MD5) %R 10.1142/S0129055X08003493 %0 Journal Article %J J. Noncomm. Geom. 1 (2007) 213-239 %D 2007 %T Dirac operators on all Podles quantum spheres %A Francesco D'Andrea %A Ludwik Dabrowski %A Giovanni Landi %A Elmar Wagner %X We construct spectral triples on all Podles quantum spheres. These noncommutative geometries are equivariant for a left action of $U_q(su(2))$ and are regular, even and of metric dimension 2. They are all isospectral to the undeformed round geometry of the 2-sphere. There is also an equivariant real structure for which both the commutant property and the first order condition for the Dirac operators are valid up to infinitesimals of arbitrary order. %B J. Noncomm. Geom. 1 (2007) 213-239 %G en_US %U http://hdl.handle.net/1963/2177 %1 2067 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2007-10-04T09:28:47Z\\nNo. of bitstreams: 1\\n0606480v2.pdf: 249691 bytes, checksum: b7ae4969eee716046a815f5e66a249fb (MD5) %R 10.4171/JNCG/5 %0 Journal Article %J Commun. Math. Phys. 263 (2006) 65-88 %D 2006 %T A Hopf bundle over a quantum four-sphere from the symplectic group %A Giovanni Landi %A Chiara Pagani %A Cesare Reina %X We construct a quantum version of the SU(2) Hopf bundle $S^7 \\\\to S^4$. The quantum sphere $S^7_q$ arises from the symplectic group $Sp_q(2)$ and a quantum 4-sphere $S^4_q$ is obtained via a suitable self-adjoint idempotent $p$ whose entries generate the algebra $A(S^4_q)$ of polynomial functions over it. This projection determines a deformation of an (anti-)instanton bundle over the classical sphere $S^4$. We compute the fundamental $K$-homology class of $S^4_q$ and pair it with the class of $p$ in the $K$-theory getting the value -1 for the topological charge. There is a right coaction of $SU_q(2)$ on $S^7_q$ such that the algebra $A(S^7_q)$ is a non trivial quantum principal bundle over $A(S^4_q)$ with structure quantum group $A(SU_q(2))$. %B Commun. Math. Phys. 263 (2006) 65-88 %G en_US %U http://hdl.handle.net/1963/2179 %1 2065 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2007-10-04T12:11:37Z\\nNo. of bitstreams: 1\\n0407342v2.pdf: 282873 bytes, checksum: e4341c8c3cce9ea132fe6c6916a61526 (MD5) %R 10.1007/s00220-005-1494-3 %0 Journal Article %J Commun. Math. Phys. 259 (2005) 729-759 %D 2005 %T The Dirac operator on SU_q(2) %A Ludwik Dabrowski %A Giovanni Landi %A Andrzej Sitarz %A Walter van Suijlekom %A Joseph C. Varilly %X We construct a 3^+ summable spectral triple (A(SU_q(2)),H,D) over the quantum group SU_q(2) which is equivariant with respect to a left and a right action of U_q(su(2)). The geometry is isospectral to the classical case since the spectrum of the operator D is the same as that of the usual Dirac operator on the 3-dimensional round sphere. The presence of an equivariant real structure J demands a modification in the axiomatic framework of spectral geometry, whereby the commutant and first-order properties need be satisfied only modulo infinitesimals of arbitrary high order. %B Commun. Math. Phys. 259 (2005) 729-759 %I Springer %G en %U http://hdl.handle.net/1963/4425 %1 4175 %2 Mathematics %3 Mathematical Physics %4 -1 %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2011-10-04T08:01:47Z No. of bitstreams: 1 math_0411609v2.pdf: 293099 bytes, checksum: cfa2846ded2ecf161e83f4269b65e9b2 (MD5) %R 10.1007/s00220-005-1383-9 %0 Journal Article %J K-Theory 35 (2005) 375-394 %D 2005 %T The local index formula for SUq(2) %A Walter van Suijlekom %A Ludwik Dabrowski %A Giovanni Landi %A Andrzej Sitarz %A Joseph C. Varilly %X We discuss the local index formula of Connes-Moscovici for the isospectral noncommutative geometry that we have recently constructed on quantum SU(2). We work out the cosphere bundle and the dimension spectrum as well as the local cyclic cocycles yielding the index formula. %B K-Theory 35 (2005) 375-394 %G en_US %U http://hdl.handle.net/1963/1713 %1 2438 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2006-01-18T10:14:50Z\\nNo. of bitstreams: 1\\nmath.QA0501287.pdf: 189281 bytes, checksum: 75a780cbe958f6093e340102ad9bf176 (MD5) %R 10.1007/s10977-005-3116-4 %0 Journal Article %J Comm. Math. Phys. 260 (2005) 203-225 %D 2005 %T Principal fibrations from noncommutative spheres %A Giovanni Landi %A Walter van Suijlekom %X We construct noncommutative principal fibrations S_\\\\theta^7 \\\\to S_\\\\theta^4 which are deformations of the classical SU(2) Hopf fibration over the four sphere. We realize the noncommutative vector bundles associated to the irreducible representations of SU(2) as modules of coequivariant maps and construct corresponding projections. The index of Dirac operators with coefficients in the associated bundles is computed with the Connes-Moscovici local index formula. The algebra inclusion $A(S_\\\\theta^4) \\\\into A(S_\\\\theta^7)$ is an example of a not trivial quantum principal bundle. %B Comm. Math. Phys. 260 (2005) 203-225 %G en_US %U http://hdl.handle.net/1963/2284 %1 1732 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2007-10-22T14:25:11Z\\nNo. of bitstreams: 1\\n0410077v3.pdf: 291352 bytes, checksum: 91d11a43e2221278d597a48ce274e4a5 (MD5) %R 10.1007/s00220-005-1377-7 %0 Journal Article %J C. R. Math. 340 (2005) 819-822 %D 2005 %T The spectral geometry of the equatorial Podles sphere %A Ludwik Dabrowski %A Giovanni Landi %A Mario Paschke %A Andrzej Sitarz %X We propose a slight modification of the properties of a spectral geometry a la Connes, which allows for some of the algebraic relations to be satisfied only modulo compact operators. On the equatorial Podles sphere we construct suq2-equivariant Dirac operator and real structure which satisfy these modified properties. %B C. R. Math. 340 (2005) 819-822 %G en_US %U http://hdl.handle.net/1963/2275 %1 1972 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2007-10-22T09:37:10Z\\nNo. of bitstreams: 1\\n0408034v2.pdf: 95565 bytes, checksum: 1c0e7836d4006a796eb943f128938773 (MD5) %R 10.1016/j.crma.2005.04.003 %0 Journal Article %J J. Geom. Phys. 49 (2004) 272-293 %D 2004 %T Fredholm modules for quantum euclidean spheres %A Eli Hawkins %A Giovanni Landi %X The quantum Euclidean spheres, $S_q^{N-1}$, are (noncommutative) homogeneous spaces of quantum orthogonal groups, $\\\\SO_q(N)$. The *-algebra $A(S^{N-1}_q)$ of polynomial functions on each of these is given by generators and relations which can be expressed in terms of a self-adjoint, unipotent matrix. We explicitly construct complete sets of generators for the K-theory (by nontrivial self-adjoint idempotents and unitaries) and the K-homology (by nontrivial Fredholm modules) of the spheres $S_q^{N-1}$. We also construct the corresponding Chern characters in cyclic homology and cohomology and compute the pairing of K-theory with K-homology. On odd spheres (i. e., for N even) we exhibit unbounded Fredholm modules by means of a natural unbounded operator D which, while failing to have compact resolvent, has bounded commutators with all elements in the algebra $A(S^{N-1}_q)$. %B J. Geom. Phys. 49 (2004) 272-293 %I SISSA Library %G en %U http://hdl.handle.net/1963/1636 %1 2482 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T13:05:40Z (GMT). No. of bitstreams: 1\\nmath.KT0210139.pdf: 218018 bytes, checksum: 44f0c66ef47d8b2e1cafc955075c7626 (MD5)\\n Previous issue date: 2002 %R 10.1016/S0393-0440(03)00092-5 %0 Journal Article %J Mod. Phys. Lett. A 18 (2003) 2371-2379 %D 2003 %T Non-linear sigma-models in noncommutative geometry: fields with values in finite spaces %A Ludwik Dabrowski %A Thomas Krajewski %A Giovanni Landi %X We study sigma-models on noncommutative spaces, notably on noncommutative tori. We construct instanton solutions carrying a nontrivial topological charge q and satisfying a Belavin-Polyakov bound. The moduli space of these instantons is conjectured to consists of an ordinary torus endowed with a complex structure times a projective space $CP^{q-1}$. %B Mod. Phys. Lett. A 18 (2003) 2371-2379 %I World Scientific %G en_US %U http://hdl.handle.net/1963/3215 %1 1086 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2008-10-30T11:23:21Z\\nNo. of bitstreams: 1\\n0309143v1.pdf: 165627 bytes, checksum: c79b1a62edf34ae51819b5e8d752db8b (MD5) %R 10.1142/S0217732303012593 %0 Journal Article %J Differential Geom. Appl. 16 (2002) 277-284 %D 2002 %T Instanton algebras and quantum 4-spheres %A Ludwik Dabrowski %A Giovanni Landi %X We study some generalized instanton algebras which are required to describe `instantonic complex rank 2 bundles\\\'. The spaces on which the bundles are defined are not prescribed from the beginning but rather are obtained from some natural requirements on the instantons. They turn out to be quantum 4-spheres $S^4_q$, with $q\\\\in\\\\IC$, and the instantons are described by self-adjoint idempotents e. We shall also clarify some issues related to the vanishing of the first Chern-Connes class $ch_1(e)$ and on the use of the second Chern-Connes class $ch_2(e)$ as a volume form. %B Differential Geom. Appl. 16 (2002) 277-284 %I Elsevier %G en_US %U http://hdl.handle.net/1963/3134 %1 1199 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2008-10-17T09:39:17Z\\nNo. of bitstreams: 1\\n0101177v2.pdf: 131163 bytes, checksum: 6756bdd801d3c677c7a70ee74fefd158 (MD5) %R 10.1016/S0926-2245(02)00066-9 %0 Journal Article %J Comm. Math. Phys. 221 (2001) 161-168 %D 2001 %T Instantons on the Quantum 4-Spheres S^4_q %A Ludwik Dabrowski %A Giovanni Landi %A Tetsuya Masuda %X We introduce noncommutative algebras $A_q$ of quantum 4-spheres $S^4_q$, with $q\\\\in\\\\IR$, defined via a suspension of the quantum group $SU_q(2)$, and a quantum instanton bundle described by a selfadjoint idempotent $e\\\\in \\\\Mat_4(A_q)$, $e^2=e=e^*$. Contrary to what happens for the classical case or for the noncommutative instanton constructed in Connes-Landi, the first Chern-Connes class $ch_1(e)$ does not vanish thus signaling a dimension drop. The second Chern-Connes class $ch_2(e)$ does not vanish as well and the couple $(ch_1(e), ch_2(e))$ defines a cycle in the $(b,B)$ bicomplex of cyclic homology. %B Comm. Math. Phys. 221 (2001) 161-168 %I Springer %G en_US %U http://hdl.handle.net/1963/3135 %1 1198 %2 Mathematics %3 Mathematical Physics %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2008-10-17T09:47:38Z\\nNo. of bitstreams: 1\\n0012103v2.pdf: 128667 bytes, checksum: 86c8b564b4eb5008fad8371fcfd5f265 (MD5) %R 10.1007/PL00005572 %0 Journal Article %J Int. J. Mod. Phys. B 14 (2000) 2367-2382 %D 2000 %T Some Properties of Non-linear sigma-Models in Noncommutative Geometry %A Ludwik Dabrowski %A Thomas Krajewski %A Giovanni Landi %X We introduce non-linear $\\\\sigma$-models in the framework of noncommutative geometry with special emphasis on models defined on the noncommutative torus. We choose as target spaces the two point space and the circle and illustrate some characteristic features of the corresponding $\\\\sigma$-models. In particular we construct a $\\\\sigma$-model instanton with topological charge equal to 1. We also define and investigate some properties of a noncommutative analogue of the Wess-Zumino-Witten model. %B Int. J. Mod. Phys. B 14 (2000) 2367-2382 %I SISSA Library %G en %U http://hdl.handle.net/1963/1373 %1 3082 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:57:00Z (GMT). No. of bitstreams: 1\\nhep-th0003099.pdf: 185777 bytes, checksum: 30806664c895808c1cb1afe5e6364f9f (MD5)\\n Previous issue date: 1999 %R 10.1142/S0217979200001898 %0 Journal Article %J Nuclear Phys. B. Proc. Suppl. 18A (1990), 171 %D 1990 %T Algebraic differential calculus for gauge theories %A Giovanni Landi %A Giuseppe Marmo %B Nuclear Phys. B. Proc. Suppl. 18A (1990), 171 %I SISSA Library %G en %U http://hdl.handle.net/1963/891 %1 2900 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:39:14Z (GMT). No. of bitstreams: 1\\n135_89.pdf: 1275996 bytes, checksum: 206cd5e78d64c8a5f30cb85a3329b5cd (MD5)\\n Previous issue date: 1989 %R 10.1016/0920-5632(90)90649-F %0 Journal Article %J J.Math.Phys.31:45,1990 %D 1990 %T Chern-Simons forms on principal superfiber bundles %A Giovanni Landi %A Claudio Bartocci %A Ugo Bruzzo %X A graded Weil homomorphism is defined for principal superfiber bundles and the related transgression (or Chern-Simons) forms are introduced. As an example of the application of these concepts, a ``superextension\\\'\\\' of the Dirac monopole is discussed. %B J.Math.Phys.31:45,1990 %I SISSA Library %G en %U http://hdl.handle.net/1963/590 %1 3314 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:34:46Z (GMT). No. of bitstreams: 1\\n109_87.pdf: 683027 bytes, checksum: c0d44fdabb8144815d764846f5241132 (MD5)\\n Previous issue date: 1987 %R 10.1063/1.528826 %0 Journal Article %J Phys. Lett. B 201 (1988), no. 1, 101-104. %D 1988 %T Algebraic reduction of the \\\'t Hooft-Polyakov monopole to the Dirac monopole. %A Giovanni Landi %A Giuseppe Marmo %B Phys. Lett. B 201 (1988), no. 1, 101-104. %I SISSA Library %G en %U http://hdl.handle.net/1963/578 %1 3326 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:34:36Z (GMT). No. of bitstreams: 1\\n97_87.pdf: 211964 bytes, checksum: 4b695a8c6442b33d501e9d46b8d1f65d (MD5)\\n Previous issue date: 1987 %R 10.1016/0370-2693(88)90088-3 %0 Thesis %D 1988 %T An Algebraic Setting for Gauge Theories %A Giovanni Landi %I SISSA %G en %U http://hdl.handle.net/1963/5828 %1 5677 %2 Mathematics %3 Mathematical Physics %4 -1 %$ Submitted by Maria Pia Calandra (calapia@sissa.it) on 2012-05-10T11:47:30Z\\nNo. of bitstreams: 1\\nPhD_Landi_Giovanni.pdf: 12850619 bytes, checksum: f875567d94d0cea44fd8c704db2b3222 (MD5) %0 Journal Article %J Phys. Lett. B 210 (1988), no. 1-2, 68--72. %D 1988 %T Einstein algebras and the algebraic Kaluza-Klein monopole. %A Giovanni Landi %A Giuseppe Marmo %B Phys. Lett. B 210 (1988), no. 1-2, 68--72. %I SISSA Library %G en %U http://hdl.handle.net/1963/603 %1 3301 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:35:21Z (GMT). No. of bitstreams: 0\\n Previous issue date: 1988 %R 10.1016/0370-2693(88)90351-6 %0 Journal Article %J Phys. Lett. B 193 (1987), no. 1, 61-66. %D 1987 %T Extensions of Lie superalgebras and supersymmetric Abelian gauge fields. %A Giovanni Landi %A Giuseppe Marmo %B Phys. Lett. B 193 (1987), no. 1, 61-66. %I SISSA Library %G en %U http://hdl.handle.net/1963/507 %1 3397 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:33:45Z (GMT). No. of bitstreams: 1\\n26_87.pdf: 406704 bytes, checksum: e30da04d568e051692076b40861772e7 (MD5)\\n Previous issue date: 1987 %R 10.1016/0370-2693(87)90456-4 %0 Journal Article %J Phys. Lett. B 192 (1987), no. 1-2, 81-88. %D 1987 %T Graded Chern-Simons terms %A Giovanni Landi %A Giuseppe Marmo %B Phys. Lett. B 192 (1987), no. 1-2, 81-88. %I SISSA Library %G en %U http://hdl.handle.net/1963/508 %1 3396 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:33:46Z (GMT). No. of bitstreams: 1\\n27_87.pdf: 430947 bytes, checksum: 98f993afd9ffd6652dc2751540a12c3c (MD5)\\n Previous issue date: 1987 %R 10.1016/0370-2693(87)91146-4 %0 Journal Article %J Phys. Lett. B 195 (1987), no. 3, 429-434 %D 1987 %T Lie algebra extensions and abelian monopoles. %A Giovanni Landi %A Giuseppe Marmo %B Phys. Lett. B 195 (1987), no. 3, 429-434 %I SISSA Library %G en %U http://hdl.handle.net/1963/506 %1 3398 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:33:44Z (GMT). No. of bitstreams: 1\\n25_87.pdf: 317945 bytes, checksum: 2115410289a4c7e0b30e696532f0568e (MD5)\\n Previous issue date: 1987 %R 10.1016/0370-2693(87)90043-8 %0 Journal Article %J Lett. Math. Phys. 11 (1986), no. 2, 171-175 %D 1986 %T The natural spinor connection on $S\\\\sb 8$ is a gauge field %A Giovanni Landi %B Lett. Math. Phys. 11 (1986), no. 2, 171-175 %I SISSA Library %G en %U http://hdl.handle.net/1963/448 %1 3455 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:32:34Z (GMT). No. of bitstreams: 0\\n Previous issue date: 1985 %0 Journal Article %J Phys. Lett. A 108 (1985), no. 7, 311-314 %D 1985 %T Flat connections for Lax hierarchies on coadjoint orbits %A Giovanni Landi %A Sergio De Filippo %B Phys. Lett. A 108 (1985), no. 7, 311-314 %I SISSA Library %G en %U http://hdl.handle.net/1963/460 %1 3443 %2 Mathematics %3 Mathematical Physics %$ Made available in DSpace on 2004-09-01T12:32:42Z (GMT). No. of bitstreams: 0\\n Previous issue date: 1985 %R 10.1016/0375-9601(85)90102-1 %0 Journal Article %J Lett. Nuovo Cim. 42 (1985) 70-72 %D 1985 %T Maximal acceleration and Sakharov's limiting temperature %A Eduardo R. Caianiello %A Giovanni Landi %X

It is shown that Sakharov's maximal temperature, derived by him from astrophysical considerations, is a straightforward consequence of the maximal acceleration introduced by us in previous works.

%B Lett. Nuovo Cim. 42 (1985) 70-72 %I Società Italiana di Fisica %G en %U http://hdl.handle.net/1963/372 %1 3595 %2 Physics %3 Elementary Particle Theory %$ Made available in DSpace on 2004-09-01T12:28:51Z (GMT). No. of bitstreams: 1\\n69_84.pdf: 77590 bytes, checksum: 43178eeeda3b943f920430cfd241f874 (MD5)\\n Previous issue date: 1984 %R 10.1007/BF02748306