One of the most efficient energy sources in the universe is the matter accretion onto compact objects, such as black holes (BHs) and neutron stars (NSs). Since magnetic fields are ubiquitous everywhere, the accretion flow is expected to be magnetized in nature, where the large-scale magnetic fields inside the disks are commonly rooted either from the companion star or the interstellar medium. Being motivated by this, we investigate the structure of low angular momentum magnetohydrodynamic (MHD) accretion flows around a Kerr BH using a general relativistic (GR) framework. To begin with, we adopt a steady, axisymmetric, advective accretion disk, which is threaded by the radial (b^r) and toroidal (b^\phi) components of magnetic fields. These magnetic field lines are frozen in the accreting plasmas following the ideal GRMHD approximation. In addition, we adopt the relativistic equation of state (variable adiabatic index \Gamma) and obtain the family of trans-fast-magnetosonic accretion solutions. In a magnetized flow, the inflowing matter experiences centrifugal repulsion and an additional barrier due to the magnetic pressure that eventually causes a discontinuous shock transition of the flow variables following the necessary jump conditions. With this, we examine the shock dynamics with the variation of radial magnetic flux (\Phi) and the iso-rotation parameter (F). It is worth mentioning that the toroidal magnetic field jumps significantly across the shock front, resulting in a highly magnetized PSC. We further identify the effective region of the parameter space for standing fast-MHD shocks and observe that shock forms for a wide range of flow parameters, namely energy (\mathcal{E}), angular momentum (\mathcal{L}), and radial magnetic flux (\Phi), respectively. Meanwhile, we observe that the shocked GRMHD flow fails to achieve the Magnetically Arrested Disk (MAD) state in the midplane, yet it sustains a ‘SANE’ (Standard And Normal Evolution) flux. It is intriguing that the present steady state formalism could be useful to provide background seed solutions to perform GRMHD simulations in higher dimensions. Finally, we comment on the possible SEDs from the GRMHD flows.
An Overview of the magnetized advective flows around black holes
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Introduction to Computer Vision with PyTorch
Black Hole Workshops
Next workshop:
XVIII Black Holes Workshop, Lisbon, 2025
18-19 December 2025
Previous workshops in the series:
I Black Holes Workshop, Porto, 2008
II Black Holes Workshop, Lisbon, 2009
III Black Holes Workshop, Minho, 2010
IV Black Holes Workshop, Aveiro, 2011
V Black Holes Workshop, Lisbon, 2012
VI Black Holes Workshop, Minho 2013
VII Black Holes Workshop, Aveiro 2014
VIII Black Holes Workshop, Lisbon 2015
IX Black Holes Workshop, Minho 2016
X Black Holes Workshop, Aveiro 2017
XI Black Holes Workshop, Lisbon, 2018
XII Black Holes Workshop, Minho, 2019
XIII Black Holes Workshop, Lisbon, 2020
XIV Black Holes Workshop, Aveiro, 2021
XV Black Holes Workshop, Lisbon, 2022
XVI Black Holes Workshop, Porto, 2023
XVII Black Holes Workshop, Aveiro, 2024
Numerical data
NewFunFICO network
Our group coordinates the Marie Sklodowska Curie Staff Exchange NewFunFiCO network (Jan 2023- Dec 2026)
More info here
FunFiCO Network
Our group coordinates the Marie Curie RISE FunFiCO network (Dec 2017- Dec 2023)
More info here
EuCAPT Consortium
GWVerse COST
StronGrHEP Network
Our group was part of the RISE StronGrHEP network (2016-2019)
Meetings:
Paris, 12-13 May 2016
Azores, 3-8 July 2017
Osaka, 4-8 September 2017
NRHEP Network Meetings
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
First Meeting:
9-13 July 2012, Aveiro, Portugal
Second Meeting:
11-14 March 2013, Lisbon, Portugal
Third Meeting:
6-10 January 2014, Mississippi, USA
Fourth Meeting:
7-10 July 2015, Rome, Italy
Fifth Meeting:
28 Sep-2 Oct 2015, Belém, Brazil
Ph.D. and Post-doctoral opportunities
Contact us If you are interested in pursuing graduate studies/research in our group.
Information for prospective Ph.D. students can be found here.
Past Ph.D. theses from our group can be found here.
Working as a researcher in Portugal - a quick guide.