@article{69388d83a4674a3bb4b2cd3ea67b29bd, title = "Horava Gravity is Asymptotically Free in 2 +1 Dimensions", abstract = "We compute the β functions of marginal couplings in projectable Ho{\v r}ava gravity in 2+1 spacetime dimensions. We show that the renormalization group flow has an asymptotically free fixed point in the ultraviolet (UV), establishing the theory as a UV-complete model with dynamical gravitational degrees of freedom. Therefore, this theory may serve as a toy model to study fundamental aspects of quantum gravity. Our results represent a step forward towards understanding the UV properties of realistic versions of Ho{\v r}ava gravity.", keywords = "High Energy Physics - Theory, General Relativity and Quantum Cosmology", author = "Barvinsky, {Andrei O.} and Diego Blas and Mario Herrero-Valea and Sibiryakov, {Sergey M.} and Steinwachs, {Christian F.}", year = "2017", month = nov, day = "24", doi = "10.1103/PhysRevLett.119.211301", language = "English", volume = "119", pages = "211301", journal = "Physical Review Letters", issn = "0031-9007", publisher = "American Physical Society (APS)", }
@article{8c3ceba41e8c4ff2b9619faade4ce83d, title = "Bounding the Speed of Gravity with Gravitational Wave Observations", abstract = "The time delay between gravitational wave signals arriving at widely separated detectors can be used toplace upper and lower bounds on the speed of gravitational wave propagation. Using a Bayesian approach thatcombines the first three gravitational wave detections reported by the LIGO Scientific and VirgoCollaborations we constrain the gravitational waves propagation speed cgw to the 90% credible interval0.55care made and as more detectors join the worldwide network. Of order 20 detections by the two LIGO detectorswill constrain the speed of gravity to within 20% of the speed of light, while just five detections by the LIGOVirgo-Kagra network will constrain the speed of gravity to within 1% of the speed of light.", keywords = "General Relativity and Quantum Cosmology, High Energy Physics - Phenomenology, High Energy Physics - Theory", author = "Neil Cornish and Diego Blas and Germano Nardini", year = "2017", month = oct, day = "20", doi = "10.1103/PhysRevLett.119.161102", language = "English", volume = "119", pages = "161102", journal = "Physical Review Letters", issn = "0031-9007", publisher = "American Physical Society (APS)", }
@article{39df179a391245e7826493f9a1b7c61e, title = "Ultralight Dark Matter Resonates with Binary Pulsars", abstract = "We consider the scenario where dark matter (DM) is represented by an ultralight classical scalar field performing coherent periodic oscillations. We point out that such DM perturbs the dynamics of binary systems either through its gravitational field or via direct coupling to ordinary matter. This perturbation gets resonantly amplified if the frequency of DM oscillations is close to a (half-)integer multiple of the orbital frequency of the system and leads to a secular variation of the orbital period. We suggest using binary pulsars as probes of this scenario and estimate their sensitivity. While the current accuracy of observations is not yet sufficient to probe the purely gravitational effect of DM, it already yields constraints on direct coupling that are competitive with other bounds. The sensitivity will increase with the upcoming radio observatories such as the Square Kilometer Array.", keywords = "High Energy Physics - Phenomenology, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena", author = "Diego Blas and Nacir, {Diana L{\'o}pez} and Sergey Sibiryakov", year = "2017", month = jun, day = "30", doi = "10.1103/PhysRevLett.118.261102", language = "English", volume = "118", pages = "261102", journal = "Physical Review Letters", issn = "0031-9007", publisher = "American Physical Society (APS)", }