21st International Conference on General Relativity and Gravitation Columbia University in the City of New York July 10th - 15th, 2016 ii Contents Session A1 1 A group theoretic approach to shear-free radiating stars (Gezahegn Zewdie Abebe)................................... 1 Separable metrics and radiating stars (Gezahegn Zewdie Abebe) . 1 Lie point symmetries, vacuum Einstein equations, and Ricci solitons (Mo- hammad Akbar).............................. 2 Open Access Non-Linear Electrodynamics Gedanken Experiment for Mod- ified Zero Point Energy and Planck's Constant, h Bar, in the Begin- ning of Cosmological Expansion, So h(Today) = h(Initial). (Andrew Beckwith) ................................. 2 Solving the Einstein-Maxwell Equations for the Propagation of Relativistic Energy during Kasner and other Anisotropic Early-Universe Models (Brett Bochner).............................. 3 Ergosphere of the Born-Infeld black hole (Nora Breton)........... 3 Elastic waves in spherically symmetric elastic spacetimes (Irene Brito,Jaume Carot, and Estelita Vaz)......................... 3 Cylindrically symmetric inhomogeneous dust collapse (Irene Brito, M. F. A. Da Silva, Filipe C. Mena and N. O. Santos)............ 4 Did GW150914 produce a rotating gravastar? (Cecilia Chirenti) . 4 The Inverse spatial Laplacian of spherically symmetric backgrounds (Karan Fernandes) ................................ 4 Coordinate families for the Schwarzschild geometry based on radial timelike geodesics (Tehani Finch)......................... 5 Rotating black hole and quintessence (Sushant Ghosh) ........... 5 The Role of an Equation of State in Modeling Relativistic Compact Stars (Megandhren Govender) ......................... 6 Causal structure of cosmological black holes under scalar-field accretion (Daniel Guariento)............................ 6 Rotating fields and the Newman-Janis algorithm in conformastatic space- times (Antonio C. Gutierrez-Pineres).................. 6 Quasi-local Energy for Black Holes (Yuan K. Ha).............. 7 Kinematic restrictions on particle collisions near extremal black holes{a unified analysis (Filip Hejda) ...................... 7 Towards a charged Myers-Perry black hole (Eric Hirschmann) . 8 The Effect of Gravitational Waves on the Nearby Particles in Closed Space- times (Jafar Khodagholizadeh)...................... 8 iii Short-Distance Gravity Interaction and Ostrogradski Formalism (Timur Kamalov) ................................. 8 Higher dimensional spacetimes with a separable Klein-Gordon equation (Ivan Kolar)................................ 9 Various limits of Kerr-NUT-(A)dS spacetimes (Pavel Krtous) . 9 Thermodynamics of Accelerating Black Holes (David Kubiznak) . 10 On Stability of the Static Charged Brans-Dicke Spacetimes (Anthony Lun) 10 Black Holes: Hovering vs falling perspectives (Colin MacLaurin) . 10 Stellar objects in the quadratic regime (Pedro Mafa Takisa) . 11 On the conditions for the formation of exotic compact objects from gravi- tational collapse (Daniele Malafarina) . 11 Universal Walker metrics (Tomas Malek)................... 12 The Cartan Algorithm in Higher Dimensions with Applications (David McNutt).................................. 12 Anisotropic dark energy cosmological model with a hybrid scale factor (Bivudutta Mishra)............................ 13 Radiating stars with exponential Lie symmetries (Rakesh Mohanlal) . 13 Stellar models generated via the horizon function (Riven Narain) . 14 Particle and photon orbits in flat and non-flat McVittie spacetimes (Brien Nolan)................................... 14 Exact solutions to Einstein's equations in the (2+2) Hamiltonian reduction formalism (Seung Hun Oh)........................ 15 Geodesically complete black hole space-times in arbitrary dimension. (Gon- zalo J. Olmo)............................... 15 Electromagnetic fields with vanishing scalar invariants (Marcello Ortaggio) 16 Algebraic classification of spacetimes - recent developments (Vojtech Pravda) 16 Universal metrics in modified theories of gravity. (Alena Pravdova) . 16 Viability of some classes of static spherically symmetric exact interior so- lutions as models for compact objects. (Ambrish Raghoonundun) . 17 Vacuum thin shells in EGB brane-world cosmology (Marcos Ramirez) . 17 Algebraically special solutions in five dimensions (Harvey Reall) . 18 The effects of self-interactions on spinning boson stars and Kerr black holes with scalar hair (Helgi Freyr R´unarsson) . 18 Hawking radiation from magnetized black holes (Khalid Saifullah) . 18 Visualizing spacetime curvature for teaching/interpreting GR (Robert Scott) 19 Study of Thin-Shell Wormholes Stability (Muhammad Sharif ) . 19 Super-Entropic Black Holes: the Kerr-CFT Correspondence (Cedric Musema Sinamuli) ................................. 20 Explicit algebraic classification of Robinson-Trautman and Kundt geome- tries (Robert Svarc)............................ 20 General Relativity and the Great War (Virginia Trimble) . 20 Late time Cosmic Acceleration with Unified Dark Fluid and a Hybrid Scale Factor (Sunil K. Tripathy)........................ 21 Violation of cosmic censorship in dynamical p-brane systems (Kunihito Uzawa) .................................. 21 iv Interpretation of Generic Off-Diagonal Exact Solutions in Einstein Gravity and Modifications (Sergiu Vacaru) ................... 22 Non-aligned Einstein-Maxwell fields (Norbert Van den Bergh) . 22 Caustic-singulartity-free scalar field theory with shift-symmetry (Yota Watan- abe) .................................... 23 Cylindrically Symmetric Static Perfect Fluid Solution of Petrov Type D (Muhammad Ziad) ............................ 23 Session A2 25 Extremal black hole initial data deformations ( Andr´esAce(n)a~ ) . 25 A study of positive energy condition in Bianchi universes via Noether sym- metries (Sajid Ali) ............................ 25 Models for self-gravitating photon shells and geons (H˚akanAndr(e)asson´ ) 26 New `hairy' black hole and soliton solutions to anti de-Sitter Einstein- Yang-Mills theories ( J. Erik Baxter ).................. 26 Energy Density Irregularities in Self-gravitating systems ( Muhammad Zaeem Ul Haq Bhatti) .......................... 27 On first integrals of the geodesic equations for spacetimes via Noether symmetry ( Ugur Camci )........................ 27 Wormholes and nonsingular space-times in Palatini f(R) gravity ( Ale- jandro Cardenas-Avendano )....................... 27 Deflection of Light in Kerr-Taub-NUT space time ( Sarani Chakraborty ) 28 The dawn of Relativistic Astrometry: what can we learn from Gaia ( Mariateresa Crosta )........................... 28 Relativistic astrometric models in comparison for future space astrometry ( Mariateresa Crosta ).......................... 28 Black hole nonmodal linear stability: the Schwarzschild (A)dS cases ( Gustavo Dotti ).............................. 29 Gravitational Redshift in Kerr-Newman Geometry (Anuj Kumar Dubey) . 29 A New Area Law in General Relativity ( Netta Engelhardt ) . 30 The Einstein flow on closed surfaces ( David Fajman ) . 30 Constrained field theories on backgrounds with horizons ( Karan Fernan- des ).................................... 31 The Space of Gravitational Degrees of Freedom ( Arthur Fischer ) . 31 Sharp asymptotics for Einstein-lambda-dust flows ( Helmut Friedrich ) . 32 Size and angular momentum of axisymmetric objects ( Maria Eugenia Gabach-Clement )............................. 32 Static spherically symmetric thin shell wormhole colliding with a spherical thin shell ( Sijie Gao ).......................... 32 Vacuum type D initial data ( Alfonso Garc´ıa-Parrado G´omez-Lobo) . 33 New conserved currents for vacuum space-times in dimension four with a Killing vector ( Alfonso Garca-Parrado Gmez-Lobo ) . 33 Gravitational wave memory in the expanding universe ( David Garfinkle ) 33 Shapes of rotating nonsingular shadows (Sushant Ghosh) . 34 Exploring black hole spacetimes with Sage Manifolds ( Eric Gourgoulhon ) 34 v Superradiant instabilities of asymptotically anti-de Sitter black holes ( Stephen Green ).............................. 35 Discrete cosmological models are piecewise silent ( Daniele Gregoris ) . 35 On Asymptotic Behaviour of 2+1 Einstein-Wave Map System ( Nishanth Gudapati )................................. 36 Scalar field critical collapse in 2+1 dimensions ( Carsten Gundlach ) . 36 Gravitational lensing beyond geometric optics ( Abraham Harte ) . 36 Investigations of the shear-free conjecture: the roles of acceleration and the use of algebraic software (Peter Huf )................ 37 A toy Penrose inequality and its proof ( Emma Jakobsson ) . 37 The vector field methods for the relativistic transport equations ( J´er´emie Joudioux )................................. 38 Geometric Inequalities Involving Mass, Angular Momentum, and Charge ( Marcus Khuri )............................. 38 Hairy black holes in the general Skyrme model ( Olga Kichakova ) . 38 Non-chaotic vacuum singularities without symmetries ( Paul Klinger) . 39 Singularity theorems in regularity C1;1 ( Michael Kunzinger ) . 39 Multisymplectic Perspective on ADM Momentum and Black Hole Entropy ( Eugene Kur ).............................. 40 The global nonlinear stability of Minkowski space for the f(R) theory of modified gravity ( Philippe G. LeFloch ) . 40 When near horizon geometries meet non-expanding horizons ( Jerzy Lewandowski ) ...................................... 41 Transverse deformations of extremal horizons ( James Lucietti ) . 41 Some applications of the theory of g-conjugation in