Signatures of Einstein-Maxwell dilaton-axion gravity from the observed jet power and the radiative efficiency

Abstract

The Einstein-Maxwell dilaton-axion (EMDA) gravity arises in the low energy effective action of the heterotic string theory and provides a simple framework to explore the signatures of the same. The dilaton and the axion fields inherited in the action from string compactifications have interesting consequences in inflationary cosmology and in explaining the present accelerated expansion of the universe. It is therefore worthwhile to search for the footprints of these fields in the available astrophysical observations. Since Einstein gravity is expected to receive quantum corrections in the high curvature domain, the near horizon regime of black holes seems to be the ideal astrophysical laboratory to test these deviations from general relativity. Exact, stationary and axisymmetric black hole solution in EMDA gravity corresponds to the Kerr-Sen spacetime which carries dilaton charge, while the angular momentum is sourced by the axion field. The ballistic jets and the peak emission of the continuum spectrum from the accretion disk are believed to be launched very close to the event horizon and hence should bear the imprints of the background spacetime. We compute the jet power and the radiative efficiency derived from the continuum spectrum in the Kerr-Sen background and compare them with the corresponding observations of microquasars. Our analysis reveals that Kerr black holes are more favored compared to Kerr-Sen black holes with dilaton charges.

Matches published version

References in corpus (32)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• The Confrontation between General Relativity and Experiment
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• Modified f(R) gravity consistent with realistic cosmology: from matter dominated epoch to dark energy universe
• First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
• Quantum Nature of the Big Bang
• Cosmological viability of f(R)-gravity as an ideal fluid and its compatibility with a matter dominated phase
• A new method for shadow calculations: application to parameterised axisymmetric black holes
• Gravitational wave searches for ultralight bosons with LIGO and LISA
• A Parallax Distance to the Microquasar GRS 1915+105 and a Revised Estimate of its Black Hole Mass
• Stochastic and resolvable gravitational waves from ultralight bosons
• Hidden symmetries, null geodesics, and photon capture in the Sen black hole
• Kerr Black Holes are Not Unique to General Relativity
• Kerr-Sen dilaton-axion black hole lensing in the strong deflection limit
• Spherically symmetric brane spacetime with bulk $f(\mathcal{R})$ gravity
• Constraining some Horndeski gravity theories
• Higher Order Terms of Kerr Parameter for Blandford-Znajek Monopole Solution
• Recurrent Acceleration in Dilaton-Axion Cosmology
• A new model for QPOs in accreting black holes: application to the microquasar GRS 1915+105
• Observational signature of a near-extremal Kerr-Sen black hole in the heterotic string theory
• Stationary Charged Scalar Clouds around Black Holes in String Theory
• Kerr-Sen Black Hole as Accelerator for Spinning Particles
• Scalar clouds around Kerr-Sen black holes
• Implications of Einstein-Maxwell dilaton-axion gravity from the black hole continuum spectrum
• Why has spacetime torsion such negligible effect on our universe?
• Low energy effective gravitational equations on a Gauss-Bonnet brane
• Axion-Dilaton Cosmology and Dark Energy
• Infrared study of H1743-322 in outburst: a radio-quiet and NIR-dim microquasar
• Test of Kerr-Sen metric with black hole observations

Cited by in corpus (12)

• Probing spacetime and accretion model for the Galactic Center: Comparison of Kerr and dilaton black hole shadows
• Thin accretion disk and shadow of Kerr-Sen black hole in Einstein-Maxwell-dilaton-axion gravity
• Blandford-Znajek Process in Quadratic Gravity
• Blandford-Znajek jets in MOdified Gravity
• Deep learning inference with the Event Horizon Telescope I. Calibration improvements and a comprehensive synthetic data library
• Signatures of Einstein-Maxwell dilaton-axion gravity from the observed quasi-periodic oscillations in black holes
• Constraining the rotating Simpson-Visser spacetime from the observed quasi-periodic oscillations in black holes
• Observed jet power and radiative efficiency of black hole candidates in Kerr + PFDM model
• Noncommutative Reissner-Nordström black hole from noncommutative charged scalar field
• Neutral particle collisions near Gibbons-Maeda-Garfinkle-Horowitz-Strominger black holes after shadow observations
• Deciphering signatures of Kerr-Sen black holes in presence of plasma from the Event Horizon Telescope data
• Universality of the Blandford-Znajek emission in stationary and axisymmetric spacetimes