Twistor Newsletter

Mathematical Institute, 24-29 St Giles', Oxford, OX1 3LB

Twistor Newsletter was an informal (often handwritten) journal whose aim was to inform those outside Oxford of the rapid developments in Roger Penrose's research group. During its 25 year lifespan, Twistor Newsletter was mimeographed and posted to those interested. It is hoped that digitizing Twistor Newsletter will bring the articles to a wider audience and provide a more permanent record of this unique publication. Twistor Newsletters 26 onwards appear below on this page.

The following is a link to a subdirectory in which scanned copies of Twistor Newsletters 1-25 can be found in more rudimentary form.

Twistor Newsletter 26 (March 1988) [ all ]

[ pp. 0 ] Front page

[ pp. 1-6 ] Twistors and conformal field theory M.A. Singer

[ pp. 7-11 ] Pretzel twistor spaces R. Penrose

[ pp. 12-15 ] A possible role of vertex operators in Singer's picture of 4D CFT Tsou S.T.

[ pp. 16-20 ] Conformal field theories and twistor diagrams A.P. Hodges

[ pp. 21-22 ] Geometry on CP^1 and the Virasoro algebra R.J. Baston

[ pp. 23 ] The geometry of pure spinors and invariant differential operators in higher dimensions R.J. Baston

[ pp. 24 ] A symplectic Penrose transform R.J. Baston

[ pp. 24 ] 2 dimensional conformal invariants R.J. Baston

[ pp. 25 ] Twistors and state-vector reduction R. Penrose

[ pp. 26-30 ] A twistor transform for the discrete series: the case of SU(2) E. Dunne and M.G. Eastwood

[ pp. 31-39 ] A conformally invariant conenction and the space of leaves of a shear free congruence T.N. Bailey

[ pp. 40-43 ] Relative cohomology power series, Robinson's theorem and multipole expansions T.N. Bailey

[ pp. 20,30,44 ] Abstracts

[ pp. 20 ] Advertisement

[ pp. 45 ] Contents



Twistor Newsletter 27 (December 1988) [ all ]

[ pp. 0 ] Front page

[ pp. 1-3 ] Topological QFT and twistors: holomorphic linking R. Penrose

[ pp. 4 ] Holomorphic linking: postscript R. Penrose

[ pp. 5-7 ] Causal relations and linking in twistor space R. Low

[ pp. 8-12 ] Connections between amplitudes in string theory and twistor diagrams A.P. Hodges

[ pp. 13-17 ] Notes on the correspondence between Feynman diagrams and twistor diagrams A.P. Hodges

[ pp. 18-19 ] A note on Pochhammer contours A.P. Hodges

[ pp. 20-23 ] Cohomology reduction through Qadir's intertwining operators K. Pulverer

[ pp. 24-26 ] Non-Haussdorf twistor spaces for Kerr and Schwarzschild J. Fletcher

[ pp. 27-28 ] A twistor transform for Hermitean symmetric spaces R. Baston

[ pp. 29 ] A conformally invariant connection T. N. Bailey

[ pp. 7,30-36 ] Abstracts

[ pp. 23 ] Advertisement

[ pp. 37 ] Contents



Twistor Newsletter 28 (March 1989) [ all ]

[ pp. 0 ] Front page

[ pp. 1-9 ] Cohomological residues S.A. Huggett and M.A. Singer

[ pp. 10-13 ] Non-Haussdorff Riemann surfaces and complex dynamical systems R. Penrose

[ pp. 14-16 ] More on the twistor description of the Kerr solution J. Fletcher

[ pp. 17-19 ] On Ward's Integral formula for the wave equation in plane-wave space-times L.J. Mason

[ pp. 20-23 ] Hypersurface twistors L.J. Mason

[ pp. 24-26 ] Some Stein complementary series for GL(4,C) E. Dunne

[ pp. 27-36 ] Double box diagrams A.P. Hodges

[ pp. 37-41 ] Pochhammer contours in twistor diagrams A.P. Hodges

[ pp. 42 ] Twistors and the Regge calculus L.J. Mason

[ pp. 9,26 ] Abstracts

[ pp. 13 ] Advertisement

[ pp. 43 ] Contents



Twistor Newsletter 29 (November 1989) [ all ]

[ pp. 0 ] Front page

[ pp. 1-5 ] A twistorial approach to the full vacuum equations L.J. Mason and R. Penrose

[ pp. 6-8 ] An alternative form of the Ernst potential J. Fletcher

[ pp. 9-13 ] Structure of the jet bundle for manifolds with conformal or projective structure R. Gover

[ pp. 14 ] A note on causal relations and twistor space R. Low

[ pp. 15 ] Harmonic morphisms and mini-twistor space K.P. Tod

[ pp. 16-18 ] Twistors and SU(3) monopoles A. Dancer

[ pp. 19-24 ] Twistor translation of Feynman vertices A.P. Hodges

[ pp. 25-30 ] Spin networks and the Jones polynomial L.H. Kauffman

[ pp. 13 ] Abstract

[ pp. 31 ] Contents



Twistor Newsletter 30 (June 1990) [ all ]

[ pp. 0 ] Front page

[ pp. 1-5 ] Light rays near i^o: a new mass positivity theorem R. Penrose

[ pp. 6-9 ] A quasi-local construction with positive mass A. Dougan and L.J. Mason

[ pp. 10-13 ] Monopoles and Yang-Baxter equations M.F. Atiyah and M.K. Murray

[ pp. 14-17 ] H-space - a universal integrable system? L.J. Mason

[ pp. 18-20 ] Some quaternionically equivalent Einstein metrics A. Swann

[ pp. 21-23 ] A non-Haussdorf mini-twistor space K.P. Tod

[ pp. 24-25 ] More on harmonic morphisms K.P. Tod

[ pp. 26 ] An algorithm for the Penrose transform R. Baston

[ pp. 27-28 ] The Penrose transform without spectral sequences R. Baston

[ pp. 29-32 ] Cohomological contours and cobord maps S. Huggett and M.A. Singer

[ pp. 33-35 ] Some new boundary-contour integrals A.P. Hodges

[ pp. 26-27 ] Some Yukawa interaction diagrams L. O'Donald and A.P. Hodges

[ pp. 38 ] Extended Regge trajectories: 12 years after R. Penrose and Tsou S.T.

[ pp. 39 ] Contents



Twistor Newsletter 31 (October 1990) [ all ]

[ pp. 0 ] Front page

[ pp. 1-5 ] Mass positivity from focussing and the structure of i^o A. Ashtekar and R. Penrose

[ pp. 6-8 ] Twistor theory for vacuum space-times: a new approach R. Penrose

[ pp. 9-13 ] A measurement process in a stationary quantum system D. Deutsch

[ pp. 14-18 ] Twistor regularisation for ultra-violet divergences A.P. Hodges

[ pp. 19-20 ] Preferred parameters on curves in conformal manifolds T. Bailey and M. Eastwood

[ pp. 21-22 ] Self-dual manifolds need not be locally conformal to Einstein T. Bailey and M. Eastwood

[ pp. 23-24 ] Families of invariants A.R. Gover

[ pp. 27-28 ] A multiplicity one theorem for the Penrose transform R. Baston

[ pp. 29-37 ] A spinor formulation for harmonic morphisms P. Baird and J.C. Wood

[ pp. 5,24-26,38 ] Abstracts

[ pp. 39 ] Contents



Twistor Newsletter 32 (March 1991) [ all ]

[ pp. 0 ] Front page

[ pp. 1-5 ] Twistors as charges for spin 3/2 in vacuum R. Penrose

[ pp. 6-7 ] On the topology of quaternionic manifolds C. Lebrun

[ pp. 8-9 ] Homogeneity of twistor spaces A.F. Swann

[ pp. 10-14 ] \Omega(2)_q-spin networks L.H. Kauffman

[ pp. 15-21 ] A new programme for light cone cuts and Yang-Mills holonomies L.J. Mason

[ pp. 14 ] A new programme for light cone cuts and Yang-Mills holonomies - Appendix L.J. Mason

[ pp. 22-30 ] New contours with boundary, higher order diagrams, regularisation and massive propogators A. Hodges

[ pp. 31-33 ] A twistor construction for gauge potentials on Minkowski space F. Muller

[ pp. 34 ] Towards twistor vacuum diagrams L. O'Donald

[ pp. 33 ] Abstract

[ pp. 35 ] Contents



Twistor Newsletter 33 (November 1991) [ all ]

[ pp. 0 ] Front page

[ pp. 1-6 ] Twistors as spin 3/2 charges continued: SL(3,C) bundles R. Penrose

[ pp. 7 ] Special 60 minute twistor seminar

[ pp. 8-10 ] The initial value problem in general relativity by power series V. Thomas

[ pp. 11-17 ] Conformal singularities and the Weyl curvature hypothesis R.P.A.C. Newman

[ pp. 18-21 ] Twistor theory and integrability L.J. Mason

[ pp. 22-24 ] The 3-wave interaction from the self-dual Yang-Mills equations K.P. Tod

[ pp. 25-30 ] Twistor diagrams in higher dimensions F. Muller

[ pp. 31-35 ] The quantum potential - possible origins? R. Jozsa

[ pp. 36-37 ] Update on one extended Regge trajectory Tsou S.T.

[ pp. 38-40 ] An inverse twistor function N.M.J. Woodhouse

[ pp. 41-44 ] Update on higher order Feynman diagrams A. Hodges

[ pp. 45 ] Contents



Twistor Newsletter 34 (May 1992) [ all ]

[ pp. 0 ] Front page

[ pp. 1-4 ] The most general (2,2) self-dual vacuum L. Haslehurst and R. Penrose

[ pp. 5-8 ] A comment on the preceding article N.M.J. Woodhouse

[ pp. 9-12 ] On impulsive gravitational waves Y. Nutku and R. Penrose

[ pp. 13-18 ] Kinking and causality A. Chamblin and R. Penrose

[ pp. 19-21 ] Growing the Kerr geometry from seed G. Burnett-Stuart

[ pp. 22-25 ] The Bogomolny hierarchy and higher order spectral problems I.A.B. Strachan

[ pp. 26-28 ] Cohomology of the scalar product diagram in higher dimensions F. Muller

[ pp. 29-31 ] Abstracts

[ pp. 32-33 ] Journal of Geometry and Physics: a special issue

[ pp. 34 ] Puzzle page

[ pp. 35 ] Contents



Twistor Newsletter 35 (Dec 1992) [ all ]

[ pp. 0 ] Front page

[ pp. 1 ] Twistor theory conference announcement

[ pp. 2-4 ] Gravitational collapse of the wave function: new thoughts R. Penrose

[ pp. 5-7 ] Metrics with SD Weyl tensor from Painleve-VI K.P. Tod

[ pp. 8-10 ] Some new scalar-flat Kahler and hyper-Kahler metrics K.P. Tod

[ pp. 11-14 ] A 'twistor transform' for complex manifolds with connection D.D. Joyce

[ pp. 15-17 ] Exceptionally vile invariants A.R. Gover

[ pp. 18-24 ] On the symmetries of reduced self-dual Yang-Mills equations L.J. Mason

[ pp. 25-27 ] Integrable systems and curved twistor spaces I.A.B. Strachan

[ pp. 28-32 ] Endomorphisms S: \otimes H^1(PT^+, O(-2)) \circlearrowleft F. Muller

[ pp. 33-35 ] Twistor description for Weyl's class of type D vacuum space-times T. von Schroeter

[ pp. 36-40 ] Solution to puzzle in TN 34 R. Penrose

[ pp. 41-42 ] Abstracts

[ pp. 43 ] Contents



Twistor Newsletter 36 (July 1993) [ all ]

[ pp. 0 ] Front page

[ pp. 1-4 ] Twistor theory conference, second announcement

[ pp. 5-9 ] Orthogonality of general spin states R. Penrose

[ pp. 9 ] A simple observation concerning {2,2} vacuums R. Penrose

[ pp. 10-11 ] The orthographic image of a regular tetrahedron M. Eastwood and R. Penrose

[ pp. 12-13 ] Indefinite, conformally-ASD metrics on S^2 x S^2 K.P. Tod

[ pp. 14-18 ] Global twistor correspondences in split signature L.J. Mason

[ pp. 19-24 ] On the dimension of elementary states R. Horan

[ pp. 25-29 ] Diagrams for tensor products of H_k, the discrete series representation of SU(1,1) with lowest weight F. Muller

[ pp. 30-32 ] Some new formulas in conformally invariant scattering A.P. Hodges

[ pp. 33-36 ] The Bach equations as an exact set of spinor fields J. Frauendiener

[ pp. 37-38 ] Twistor classification of type D vacuum space-times T. von Schroeter

[ pp. 4,36 ] Abstracts

[ pp. 39 ] Contents



Twistor Newsletter 37 (April 1994) [ all ]

[ pp. 0 ] Front page

[ pp. 1-6 ] Spin 3/2 fields and local twistors L.J. Mason and R. Penrose

[ pp. 7-9 ] Another view at the spin 3/2 equation J. Frauendiener

[ pp. 10-13 ] A higher spin generalisation of the Dirac equation to arbitrary curved manifolds J. Frauendiener

[ pp. 16-19 ] On the X-Ray, Radon and Penrose transform L.J. Mason

[ pp. 21-24 ] Update on the massive propogator in twistor diagrams A.P. Hodges

[ pp. 14,15,20 ] Abstracts

[ pp. 25 ] Contents



Twistor Newsletter 38 (October 1994) [ all ]

[ pp. 0 ] Front page

[ pp. 1-9 ] A twistor topological approach to the Einstein equations R. Penrose

[ pp. 10-11 ] Deformed twistor spaces and the KP equation I.A.B. Strachan

[ pp. 12-16 ] Reduced hypersurface twistor spaces M. Dunn

[ pp. 17-21 ] A twistor construction of irreducible torsion-free G-structures S. Merkulov

[ pp. 22-27 ] Some remarks on the stabilizer of the space of Hill operators and C. Neumann system P. Guha

[ pp. 30-34 ] The geometry of non-intersecting null rays T. Field

[ pp. 35-37 ] Progress with the massive propogator in twistor diagrams A.P. Hodges

[ pp. 38-42 ] Some calculational results for the massive propagator in twistor diagrams S. Spence

[ pp. 28-29 ] Abstracts

[ pp. 34,42 ] Conference proceedings

[ pp. 43 ] Contents



Twistor Newsletter 39 (May 1995) [ all ]

[ pp. 0 ] Front page

[ pp. 1-5 ] Concerning space-time points for spin 3/2 twistor spaces R. Penrose

[ pp. 6-10 ] Spin 3/2 zero rest mass fields in the Schwarzschild space-time J.P. Nicolas

[ pp. 11-18 ] Two examples of classical scattering off fixed sources I. Roulstone

[ pp. 19-24 ] Self-dual Einstein metrics with symmetry K.P. Tod

[ pp. 25-28 ] 'Moving-zero' solutions of Ward's chiral model G. Kelly

[ pp. 29-38 ] Complex structures via 3 and 4-dimensional Cauchy integrals T. Field

[ pp. 39-44 ] A minimum principle for the cohomological inner product on twistor space F. Muller

[ pp. 45-46 ] Conference announcement

[ pp. 47 ] Contents



Twistor Newsletter 40 (January 1996) [ all ]

[ pp. 0 ] Front page

[ pp. 1-12 ] New ideas for the googly graviton R. Penrose

[ pp. 13-19 ] Two point norms for massless fields T. Field

[ pp. 20-21 ] The Rarita-Schwinger equation for Einstein-Maxwell space-times K.P. Tod

[ pp. 22-25 ] Conference announcement

[ pp. 26-30 ] In search of a twistor correspondence for the KP equation S. Barge

[ pp. 31-36 ] On group theoretic aspects of the nonlinear twistor transform S. Merkulov

[ pp. 37-42 ] Cohomology of a quaternionic complex R. Horan

[ pp. 43-45 ] A nonlinear graviton from the sine-Gordon equation M. Dunajski

[ pp. 46 ] Abstracts

[ pp. 47 ] Contents



Twistor Newsletter 41 (August 1996) [ all ]

[ pp. 0 ] Front page

[ pp. 1-5 ] Incidence between complex null rays R. Penrose

[ pp. 6-14 ] Coherent states and Fubini-Study geometry T. Field

[ pp. 15-22 ] Quantum electrodynamic birdtracks L.H. Kauffman

[ pp. 23-25 ] Where are the twistors in the null-surface formulation of GR? S. Fritelli, C.N. Kozameh and E.T. Newman

[ pp. 26-34 ] Heavenly hierarchies and curved twistor spaces M. Dunajski and L.J. Mason

[ pp. 35-36 ] Formal adjoints and cononical form for linear operators M. Eastwood and A.R. Gover

[ pp. 37 ] Puzzles

[ pp. 38 ] Conference proceedings

[ pp. 39 ] Contents



Twistor Newsletter 42 (March 1997) [ all ]

[ pp. 0 ] Front page

[ pp. 1-5 ] Five things you can do with a surface in PT R. Penrose

[ pp. 6-11 ] Initial value problem of the colliding plane-wave K-Y. Tee

[ pp. 12 ] Divergence-free geodesic congruences in R^3 K.P. Tod

[ pp. 13-15 ] 'Special' Einstein-Weyl spaces K.P. Tod

[ pp. 16-21 ] Integrable flows on moduli of rational curves with normal bundle O^A(n) M. Dunajski and L.J. Mason

[ pp. 22 ] Asymptotic Young tableaux for discrete series F. Muller

[ pp. 23-24 ] Coherent quantum measurements T. Field

[ pp. 25-26 ] Solutions to puzzles in TN41

[ pp. 27 ] Contents



Twistor Newsletter 43 (November 1997) [ all ]

[ pp. 0 ] Front page

[ pp. 1-4 ] Googly maps as forms R. Penrose

[ pp. 5-6 ] A letter from R. Penrose H. Urbantke

[ pp. 7-10 ] Four twistor particles Z. Perjes

[ pp. 11-12 ] Average marginally-trapped surfaces in flat space K.P. Tod

[ pp. 13 ] 'Special' Einstein-Weyl spaces from the heavenly equation K.P. Tod and M. Dunajski

[ pp. 14-21 ] Singularities of wavefronts and light-cones in the context of GR via null foliations S. Fritelli and E.T. Newman

[ pp. 22-23 ] Triviality of the Grassmann bundles on hypersurfaces in R^{m+1} A. Trautman

[ pp. 24-29 ] A recursion operator for ASD vacuums and z.r.m. fields on ASD backgrounds M. Dunajski and L.J. Mason

[ pp. 30-33 ] An integral formula in general relativity J, Frauendiener

[ pp. 34 ] Corrections to misprints in solutions to TN41 puzzles

[ pp. 35 ] Contents



Twistor Newsletter 44 (August 1998) [ all ]

[ pp. 1-9 ] The twistor space for a strongly asymptotically flat vacuum R. Penrose

[ pp. 10-11 ] Extending half flat metrics D. Robinson

[ pp. 12-19 ] The abstract twistor space of the Schwarzschild space-time Z. Perjes and G. Sparling

[ pp. 20-22 ] The geometry of twistor diagrams A.P. Hodges

[ pp. 23-26 ] Exceptional hyperKahler reductions A. Swann and P. Kobak

[ pp. 27 ] Contents



Twistor Newsletter 45 (August 2000) [ all ]

[ pp. 0 ] Front page

[ pp. 1-24 ] On extracting the googly information R. Penrose

[ pp. 25-31 ] Twistors and Legendre transforms S. Frittelli, F. Hadrovich, L.J. Mason and E.T. Newman

[ pp. 32-35 ] Real Lorentzian metrics from complex, half-flat solutions D. Robinson

[ pp. 36-39 ] Combinatorics and field theory C.M. Bender, D.C. Brody, and B.K. Meister

[ pp. 40-43 ] Classical fields as statistical states D.C. Brody and L.P. Hughston

[ pp. 44-49 ] Solving polynomial equations with spinors M. Eastwood

[ pp. 50-51 ] A conjectured form of the Goldberg-Sachs theorem A. Trautman

[ pp. 52-56 ] Three stories about epsilon L. Kauffman

[ pp. 57-61 ] ASD four-manifolds and Frobenius manifolds G. Sanguinetti and N.M.J. Woodhouse

[ pp. 62-65 ] ASD null Kahler metrics with symmetry M. Dunajski

[ pp. 66 ] Announcements

[ pp. 67 ] Contents

