522 citations · 1.4k across the 29 of their papers we have counts for
29 papers
Global existence for a Fritz John equation in expanding FLRW spacetimes
João L. Costa, Jesús Oliver, Flavio Rossetti
We study the family of semilinear wave equations , on fixed expanding FLRW spacetimes, having spatial slices and undergoing…
Message in a bottle: energy extraction from bouncing geometries
Vitor Cardoso, João L. Costa, José Natário +1
Quantum gravity phenomenology suggests the interesting possibility that black holes are not eternal. Collapse could be halted by some unknown mechanism, or Hawking radiation might…
Wide neural networks: From non-gaussian random fields at initialization to the NTK geometry of training
Luís Carvalho, João Lopes Costa, José Mourão +1
Recent developments in applications of artificial neural networks with over parameters make it extremely important to study the large behaviour of such networks. Mo…
Improved decay estimates and -asymptotic stability of solutions to the Einstein-scalar field system in spherical symmetry
João L. Costa, Rodrigo Duarte, Filipe C. Mena
We investigate the asymptotic stability of solutions to the characteristic initial value problem for the Einstein (massless) scalar field system with a positive cosmological consta…
Spectral and steady-state properties of fermionic random quadratic Liouvillians
João Costa, Pedro Ribeiro, Andrea de Luca +2
We study spectral and steady-state properties of generic Markovian dissipative systems described by quadratic fermionic Liouvillian operators of the Lindblad form. The Hamiltonian…
Semilinear wave equations on accelerated expanding FLRW spacetimes
João L. Costa, Anne T. Franzen, Jesús Oliver
We identify a large class of systems of semilinear wave equations, on fixed accelerated expanding FLRW spacetimes, with nearly at spatial slices, for which we prove small data futu…