Gravitational waves – Publication of a new review paper

M. Cerdonio, G. Losurdo – Rivista del Nuovo Cimento, 35, 389, 2012

“The purpose of this review is to give an outlook on the initial crop of GW observations, on their impact in fundamental physics, in relativistic astrophysics and in cosmology, and give also an updated view of the methods and technologies, which are making possible the historical achievement of opening the era of GW astronomy.” (From the abstract)

“The review paper “Gravitational waves from discovery to astronomy” by M. Cerdonio and G. Losurdo is a remarkable piece of scientific work (…)
Starting from first principles, the physics and technology involved in the contemporary search for gravitational wave is well described. In particular, some key physics issues, usually overlooked in other reviews, are here nicely analyzed. The perspectives of the field are clearly illustrated.” (From the referee’s report)

Excellent research published online: Newtonian Gravity and the Bargmann Algebra

Dear Colleagues,

It gives me great pleasure to notify you of the publication of the above article in Classical and Quantum Gravity.

TITLE: Newtonian Gravity and the Bargmann Algebra
AUTHORS: Roel Andringa, Eric Bergshoeff, Sudhakar Panda and Mees de Roo

This article received very positive comments and a high quality rating from its referees. The article is available to download from IOPscience.

Please find below a summary by the authors of the developments made in this article:

‘Newton–Cartan gravity is a geometric formulation of Newtonian gravity, based on the nonrelativistic limit of general relativity. In our paper we confront this traditional view of Newton–Cartan gravity with a different approach that starts from the Bargmann algebra, a centrally extended version of the Galilei algebra. This approach emphasizes the analogy with the formulation of general relativity as a gauge theory of the Poincaré algebra. The algebraic method suggests a number of generalizations, for instance to conformal algebras, and to the Newton–Hooke algebra, which would lead to classical gravity induced by nonrelativistic strings.’

Yours sincerely

Rachel Lawless
Publishing Editor
Classical and Quantum Gravity

High quality article in Classical and Quantum Gravity

Dear Colleagues,

TITLE: Lost in translation: topological singularities in group field theory
AUTHORS: Razvan Gurau

It gives me great pleasure to notify you of the publication of the above article in Classical and Quantum Gravity. This article received very positive comments and a high quality rating from its referees. The article is available to download here: http://herald.iop.org/link/4107

Please find a summary of the developments made in this article below:

Random matrix models generalize in higher dimensions to Group Field Theories (GFTs) whose Feynman graphs are dual to gluings of simplices. In this paper we prove that the effective behavior of generic GFTs is dominated by singular graphs, not dual to normal simplicial pseudo manifolds. This very serious problem brings into question their viability as quantum field theories. We prove however that, fortunately, the recently introduced “colored” GFT models circumvent this problem, generating only graphs dual to pseudo manifolds. We conclude that they are the correct starting point for the study of GFTs as quantum field theories.

Yours sincerely

Adam Day
Publisher
Classical and Quantum Gravity

Read the Classical and Quantum Gravity Highlights of 2009-2010

Dear Colleagues,

I am delighted to announce the publication of Classical and Quantum Gravity’s Highlights of 2009-2010. The articles in the list, published between May 2009 and June 2010, were selected by the Editorial Board of Classical and Quantum Gravity (CQG) as a representation of the best recent work in gravitational physics.

http://herald.iop.org/link/4077

The list includes research Papers, Fast Track Communications, review articles and special issue contributions. The selected articles have also proven popular with our readers and have been frequently downloaded.

Look out for the CQG Highlights Brochure in 2011, which will be available at gravitational physics meetings. The brochure summarises the highlighted papers and will tell you more about the journal’s ongoing activities including prize sponsorships and forthcoming special issues.

I invite you to submit your work to CQG and look forward to seeing it promoted as a CQG Highlight in the future.

Yours sincerely

Adam Day
Publisher
Classical and Quantum Gravity

Excellent research published online: Combining gravity with the forces of the standard model on a cosmological scale

Dear Colleagues,

TITLE: Combining gravity with the forces of the standard model on a cosmological scale
AUTHORS: Claus Gerhardt

It gives me great pleasure to notify you of the publication of the above article in Classical and Quantum Gravity.

This article received very positive comments and a high quality rating from its referees. The article is available to download here:

http://herald.iop.org/branding/m19/rzl/$CONTACT_ID/link/3780

Please find a summary of the developments made in this article written by the authors below:

We prove the existence of a spectral resolution of the Wheeler-DeWitt equation when the underlying spacetime is a Friedman universe with flat spatial slices and where the matter fields are comprised of the strong interaction, with SU(3) replaced by a general SU(n), n >= 2, and the electro-weak interaction.

The wave functions are maps from R[4n+10] to a subspace of the antisymmetric Fock space, and one noteworthy result is that, whenever the electro-weak interaction is involved, the image of an eigenfunction is in general not one dimensional, i.e., in general it makes no sense specifying a fermion and looking for an eigenfunction the range of which is contained in the one dimensional vector space spanned by the fermion

Yours sincerely

Adam Day
Publisher
Classical and Quantum Gravity

Excellent research published online: Accurate light-time correction due to a gravitating mass

Dear Colleagues,

TITLE: Accurate light-time correction due to a gravitating mass
AUTHORS: Neil Ashby, Bruno Bertotti

It gives me great pleasure to notify you of the publication of the above article in Classical and Quantum Gravity.

This article received very positive comments and a high quality rating from its referees. Please find a summary of the developments made in this article below:

The time delay and deflection of light passing between two points near a spherical mass of gravitational radius m, are expressed to second order in m in terms of endpoint positions and angle subtended at the source by the endpoints, instead of unknown quantities such as the closest approach distance b. We minimize Fermat’s action functional and solve the eikonal equation for a null geodesic. In a close superior conjunction the second-order correction contains an enhanced part of order m2R/b2, where R is of the order of the endpoint distances from the sun. We compare these results to previous calculations, in particular with the second-order terms introduced in NASA’s Orbit Determination Program. We use asymptotic series to determine which higher-order terms are important.

The results are significant for understanding the results of the Cassini light-time experiment, and for future missions whose purpose may include measuring the PPN parameter gamma.

Yours sincerely

Adam Day
Publisher
Classical and Quantum Gravity

Excellent research published online: Reduced Hamiltonian for next-to-leading order Spin-Squared Dynamics of General Compact Binaries

Dear Colleagues,

TITLE: Reduced Hamiltonian for next-to-leading order Spin-Squared Dynamics of General Compact Binaries
AUTHORS: Steven Hergt, Jan Steinhoff and Gerhard Schaefer

It gives me great pleasure to notify you of the publication of the above article in Classical and Quantum Gravity.

This article received very positive comments and a high quality rating from its referees.

Please find a summary of the developments made in this article below:

Fully reduced Hamiltonians belong to the most compact and elegant dynamical devices in physics. This particularly applies to spinning compact binaries in general relativity where approximate Hamiltonians are now available including spin-orbit, spin(1)spin(2), and spin-squared terms, all through next-to-leading order (NLO) in relativistic coupling counted in powers of the inverse of speed-of-light squared, called post-Newtonian expansion. The most complicated terms are the spin-squared ones which include information about the rotational deformation of black holes and, depending on a specific model, of neutron stars. For both a fully reduced NLO spin-squared Hamiltonian is derived and compared with former results from the Effective Field Theory approach where a nonreduced effective potential was obtained which is cast into Hamilton form under variable transformation applicable to all NLO spin terms. The result should have impact on the description of inspiralling binaries in gravitational wave astronomy.

Yours sincerely

Adam Day
Publisher
Classical and Quantum Gravity

Iopscience.org/cqg

GW Notes: New issue and highlight on EMRI waveforms

It is a pleasure for us to announce the third issue of GW Notes. This issue’s invited article by Nicolas Yunes is focussing on “Gravitational Wave Modelling of Extreme Mass Ratio Inspirals and the Effective-One-Body Approach”.

The electronic journal “GW Notes” <http://brownbag.lisascience.org/lisa-gw-notes/> and its blog “The LISA Brownbag” <http://brownbag.lisascience.org/> , both produced by the AEI, propose to offer scientists of the Gravitational Wave community the opportunity to more easily follow advances in the areas of astrophysics, general relativity and data analysis. We hope to achieve this by selecting the most significant e-prints and listing them in abstract form with a link to the full paper in both a single e-journal (GW Notes) and a blog (The LISA Brownbag).

Of course, this also implies that the paper will have increased impact, since it will reach a broader public, and so we encourage you to not forget submitting your own work.

Best regards,

Bernard Schutz and Pau Amaro-Seoane