Abstract: Recently it has been realized that subleading corrections to soft theorems in gauge theories and gravity are related to the asymptotic symmetries of the theory at null infinity. In this talk I will discuss how in the case of the soft graviton theorem these corrections, when written in terms of kinematic invariants, exhibit a double copy structure for the emitted graviton. This result holds also in the Gribov limit, where emitted gravitons are not necessarily soft.
A large review paper, "Testing General Relativity with past and future Astrophysical observations", arXiv:1501.07271, has been made public, prepared as a Topical Review for CQG. The review includes contributions from many international experts, including from our group, and was led by Emanuele Berti. Thank you Emanuele for pushing this team effort!
Here, the numerical data described in the paper "Construction and physical properties of Kerr black holes with scalar hair", arXiv:1501.04319 [gr-qc], is made available for public use.
This paper is an invited contribution to the Focus Issue on "Black holes and fundamental fields" to appear in Classical and Quantum Gravity, Edited by Paolo Pani and Helvi Witek.
2015 marks the centennial of the General Theory of Relativity (GR), presented by Albert Einstein in 1915. Motivated by this celebration, understanding that GR is an important part of the scientific world heritage and recognizing the growing international influence of Portuguese researchers working in this area, the "Portuguese Society of Relativity and Gravitation" (SPRG) was formally established in 2015.
Abstract: We revisit the relativistic restricted two-body problem with spin employing a perturbation scheme based on Lie series. Starting from a post-Newtonian expansion of the field equations, we develop a first-order secular theory that reproduces well-known relativistic effects such as the precession of the pericentre and the Lense-Thirring and geodetic effects. Additionally, our theory takes into full account the complex interplay between the various relativistic effects, and provides a new explicit solution of the averaged equations of motion in terms of elliptic functions. Our analysis reveals the presence of particular configurations for which non-periodical behaviour can arise. The application of our results to real astrodynamical systems (such as Mercury-like and pulsar planets) highlights the contribution of relativistic effects to the long-term evolution of the spin and orbit of the secondary body.
C. Herdeiro was the guest interviewee of Porto Canal's "Mentes que Brilham". Watch and listen to the conversation with interviewer Cláudia Fonseca about black holes and some of the research work made at Gr@v in this area.
Abstract: It has been known for some time that the black hole uniqueness theorem does not extend to higher dimensional spacetimes. I will argue that the classification of five dimensional asymptotically flat black hole solutions is far from complete, even for solutions with the same symmetry as the known spherical black holes and black rings.
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
