The Lazarus Project
Intensive efforts have been underway in the past decade to write
numerical codes able to solve Einstein's system of ten coupled
nonlinear partial differential equations, on powerful supercomputers;
so far the numerical treatment of black hole systems in full 3D has
proved very difficult. Motivated by the desire to provide expectant
gravitationalwave observers with some estimate of the full merger
waveforms, and to prepare the arena for future, more advanced
numerical simulations, we have recently pursued a hybrid approach to
the problem, called the Lazarus project.
The underlying idea of Lazarus is very simple (see Figure): apply the
farlimit (FL), fullnumerical (FN) and closelimit (CL) treatments in
sequence. In this way we can restrict the finite time interval of full
nonlinear numerical evolution to covering the stage of the dynamics
where no perturbative approach is applicable, and still derive the
complete black hole ringdown and the propagation of radiation into
the wave zone with a close limit perturbative treatment. The
perturbative model not only allows an inexpensive and stable
continuation of the evolution (which is then allowed to rise and live
again like the biblical Lazarus), but also supplies a clear
interpretation of the dynamics not manifest in the generic numerical
simulation.


We have successfully addressed the problem of combining the
closelimit approximation describing ringing black holes and full
numerical relativity, required for essentially nonlinear interactions,
producing the first calculation of complete plunge waveforms, total
gravitational energy, angular momentum radiated from the coalescence
of two black holes from an estimate of the innermost stable circular
orbit down to the final single rotating black hole.
Our work has been featured in the "News and Views" section of Nature (see the picture
story ). Our latest results were used in a groundbreaking
article in Science to improve an astrophysical model on radiojet
evidence for supermassive black holes.
Future Directions
Our next goal is to refine our approach, and working together with
several colleagues in the numerical relativity group, to extend the
duration of the numerical simulations to permit studies of more
separated black hole configurations. The reason is that we would like
to build a connection to more astrophysically realistic initial data
descriptions such as with a true interface to the postNewtonian
approximation.
We are also particularly interested in using the machinery of the
Lazarus project as a tool to improve detection strategies for black
hole collision waveforms (the Kudu
project). The first step will be to explore the dependence of the
waveforms on the astrophysical parameters, such as mass ratios and
spin magnitudes and orientation, for blackhole binary systems.
We are working on extending Lazarus by using the quasiKinnersley
tetrad. The resulting Lazarus 2 will be more
robust than original Lazarus.
Papers

Gravitational
Waves from Black Hole Collisions via an Eclectic Approach
J. Baker, B. Brügmann, M. Campanelli, and C. O. Lousto;
Class. Quantum Grav. 17 (2000) L149L156

Original paper: Plunge
Waveforms from Inspiralling Binary Black Holes
J. Baker, B. Brügmann, M. Campanelli, C. O. Lousto, and
R. Takahashi
Phys. Rev. Lett. 87 (2001) 121103

Detailed Theory Paper: "The Lazarus
project: A pragmatic approach to binary black hole evolution"
J. Baker, M. Campanelli, and C. O. Lousto
Phys. Rev. D 65 (2002) 044001

Main Results Paper: "Modeling
gravitational radiation from coalescing binary black holes"
J. Baker, M. Campanelli, C. O. Lousto, and R. Takahashi
Phys. Rev. D 65 (2002) 124012

Coalescence remnant of spinning binary black holes
J. Baker, M. Campanelli, C. O. Lousto, and R. Takahashi
Phys. Rev. D 69 (2004) 027505

Lazarus2 paper: "The Lazarus project. II. Spacelike extraction with the quasiKinnersley tetrad"
M. Campanelli, B. J. Kelly, and C. O. Lousto
Phys. Rev. D 73 (2006) 064005
Talks

"Lazarus2: Applying the quasiKinnersley Frame in the Lazarus Project"  talk by Bernard Kelly, Penn State Sources & Simulations Seminar September 29, 2005

LSC
Meeting Transparencies by Manuela Campanelli, LIGO Livingston Observatory,
Livingston, Louisiana March 2023, 2002

See also the Feichtbereit
Talk by Manuela Campanelli, AEI September 2001.

See also the Numerical
Relativity and Black Hole Collisions at the 20th Texas Symposium on
Relativistic Astrophysics by Pablo Laguna, February 2001.

Literature
Catalog: Black Hole Ringdown Sources AstroGravS: Astrophysical GravitationalWave
Source Archive at the Laboratory for
High Energy Astrophysics, NASA Goddard.

"Black hole mergers: from simulation to detection" Invited Talk given
by Manuela Campanelli at the LSC Workshop 3/20/2002. (PPT,
PDF)

"An Eclectic Approach to Binary Black Hole Collisions" Talk at ITP
(Trieste) by John Baker June 2000.
Related Astrophysics
Images and Movies
Media Comments

The
Lazarus Project: Numerical relativity meets perturbation theory by
Richard Price, Matters Of Gravity: The Newsletter Of The APS Topical Group
On Gravitation. Vol.19,
ISSN pp 15273431 (Feb. 2002).

See also the
Gravitational
Wave Source Simulation program at Caltech (topic
n.6).
 Lazarus

"Scientists
Visualize Waves in Space Caused by Mergers of Black Holes" Pennsylvania
State University News Release, July 24, 2002.

"Scientists
model waves caused by black hole mergers" "SpaceFlight Now
Breaking News", July 25, 2002.

"Scientists
Visualize Waves In Space Caused By Mergers Of Black Holes"Space
Daily, Your Portal to Space, July 26, 2002.

Black
Holes collide in computer by Will Knight, NewScientist.com's news service,
July 26, 2002.

"Black
holes take the plunge" by Bernard Schutz (Max Planck Society for
the Advancement of Science, Press and Public Relations Department,
September 13, 2001)

"Black
holes take the plunge" Cosmiverse Space News, September 14, 2001

"Computer
Simulations Predict What Astronomers Will See With Gravitational Wave Telescopes
When Two Black Holes Collide" by Editor (Science
Daily, September 19, 2001)

"Schwarze
Loecher "Lazarus"Team simuliert Kollision" by the Editor of (Astronews,
September 20, 2001)

"MasseMonster
aus der Urzeit des Weltalls" by Von Ina Helms (Berliner
Morgenpost, September 20, 2001)

"Gravitational
physics: Black hole blockbuster" by Sarah Tomlin (Nature,
[PDF] October 4, 2001)

"Schwerkraftwellen
erstmals sichtbar" by Bernard Schutz (National Geographic, November
11, 2001)

"Unsichtbares
Universum: Kollisionen, die im Raum Wellen schlagen" by Thomas Buerke
(MaxPlanckForshung Vol. 4[PDF#1,
PDF#2, PDF#3,
PDF#4], 2001)