Publications

Journal Publications

Friedmann-like universes with non-metricity

D. Iosifidis, I.G. Vogiatzis and C.G. Tsagas, Eur. Phys. J. C 83, 216 (2023).

Peculiar velocities in the early universe

M. Maglara and C.G. Tsagas, Phys. Rev. D 106, 083505 (2022).

The deceleration parameter in `tilted' universes: generalising the Friedmann background

C.G. Tsagas, Eur. Phys. J. C 82, 521 (2022).

Observational constraints on the deceleration parameter in a tilted universe

K. Asvesta, L. Kazantzidis, L. Perivolaropoulos and C.G. Tsagas, Mon. Not. R. Astron. Soc. 513, 2394 (2022).

How the magnetic field behaves during the motion of a highly conductive fluid

under its own gravity: a new theoretical. relativistic aproach

P. Mavrogiannis and C.G. Tsagas, Phys. Rev. D 104, 124053 (2021).

Electromagnetic potentials in curved spacetimes

P. Mavrogiannis and C.G. Tsagas, Class. Quantum Grav. 38, 235002 (2021).

The deceleration parameter in `tilted' Friedmann universes: Newtonian vs relativistic treatment

C.G. Tsagas, M.I. Kadiltzoglou and K. Asvesta, Astrophys. Space Sci. 366, 90 (2021).

Melvin's ``magnetic universe'', the role of the magnetic tension and the implications for gravitational collapse

C.G. Tsagas and P. Mavrogiannis, Class. Quantum Grav. 38, 195020 (2021).

The peculiar Jeans length

C.G. Tsagas, Eur. Phys. J. C 81, 753 (2021).

Large-scale peculiar velocity fields: Newtonian vs relativistic treatment

K. Filippou and C.G. Tsagas, Astrophys. Space Sci. 366, 4 (2021).

Kinematical and dynamical aspects of ghost-matter cosmologies

A. Chavda, J.D. Barrow and C.G. Tsagas, Class. Quantum Grav. 37, 205010 (2020).

Relativistic approach to the kinematics of large-scale peculiar motions

E. Tsaprazi and C.G. Tsagas, Eur. Phys. J. C 80, 757 (2020).

Friedmann-like universes with weak torsion: a dynamical system approach

J.D. Barrow, C.G. Tsagas and G. Fanaras, Eur. Phys. J. C 79, 764 (2019).

Torsion/non-metricity duality in f(R) gravity

D. Iosifidis, A.C. Petkou and C.G. Tsagas, Gen. Rel. Grav. 51, 66 (2019).

Friedmann-like universes with torsion

D. Kranas, C.G. Tsagas, J.D. Barrow and D. Iosifidis, Eur. Phys. J. C 79, 341 (2019).

Raychaudhuri equation with torsion and non-metricity

D. Iosifidis, C.G. Tsagas and A.C. Petkou, Phys. Rev. D 98, 104037 (2018).

Gravitational convergence, shear deformation and rotation of magnetic forcelines

V. Giantsos and C.G. Tsagas, Mon. Not. R. Astron. Soc. 472, 869 (2017).

Kinematics of Einstein-Cartan universes

K. Pasmatsiou, C.G. Tsagas and J.D. Barrow, Phys. Rev. D 95, 104007 (2017).

Causality, initial conditions, and inflationary magnetogenesis

C.G. Tsagas, Phys. Rev. D 93, 103529 (2016).

Gravitational-wave implications for structure formation: A second-order approach

D. Pazouli and C.G. Tsagas, Phys. Rev. D 93, 063520 (2016).

Magnetised cosmological perturbations in the post-recombination era

H. Vasileiou and C.G. Tsagas, Mon. Not. R. Astron. Soc. 455, 2500 (2016).

Relaxing the limits on inflationary magnetogenesis

C.G. Tsagas, Phys. Rev. D 92, 101301(R) (2015).

Deceleration parameter in tilted Friedmann universes

C.G. Tsagas and M.I. Kadiltzoglou, Phys. Rev. D 92, 043515 (2015).

Vorticity survival in magnetised Friedmann universes

F. Dosopoulou and C.G. Tsagas, Phys. Rev. D 89, 103519 (2014).

Peculiar Raychaudhuri equation

C.G. Tsagas and M.I. Kadiltzoglou, Phys. Rev. D 88, 083501 (2013).

Gravito-electromagnetic resonances in Minkowski space

A.P. Kouretsis and C.G. Tsagas, Phys. Rev. D 88, 044006 (2013).

Do intergalactic magnetic fields imply an open universe?

J.D. Barrow, C.G Tsagas and K. Yamamoto, Phys. Rev. D 86, 107302 (2012).

Dark flows and the cosmological axis

C.G. Tsagas, Mon. Not. R. Astron. Soc. Lett. 426, L36 (2012).

Origin of cosmic magnetic fields: Superadiabatically amplified modes in open Friedmann universes

J.D. Barrow, C.G. Tsagas and K. Yamamoto, Phys. Rev. D 86, 023533 (2012).

Vorticity production and survival in viscous and magnetised cosmologies

F. Dosopoulou, F. Del Sordo, C.G. Tsagas and A. Brandenburg, Phys. Rev. D 85, 063514 (2012).

Peculiar motions, accelerated expansion and the cosmological axis

C.G. Tsagas, Phys. Rev. D 84, 063503 (2011).

Gravitoelectromagnetic resonances

C.G. Tsagas, Phys. Rev. D 84, 043524 (2011).

Primordial magnetogenesis

A. Kandus, K.E. Kunze and C.G. Tsagas, Phys. Rep. 505, 1 (2011).

Cosmological magnetic field survival

J.D. Barrow and C.G. Tsagas, Mon. Not. R. Astron. Soc. 414, 512 (2011).

Raychaudhuri's equation and aspects of relativistic charged collapse

A.P. Kouretsis and C.G. Tsagas, Phys. Rev. D 82, 124053 (2010).

Large-scale peculiar motions and cosmic acceleration

C.G. Tsagas, Mon. Not. R. Astron. Soc. 405, 503 (2010).

Gravitomagnetic amplification in cosmology

C.G. Tsagas, Phys. Rev. D 81, 043501 (2010).

On the stability of static ghost cosmologies

J.D. Barrow and C.G. Tsagas, Class. Quantum Grav. 26, 195003 (2009).

Relativistic cosmology and large-scale structure
C.G. Tsagas, A. Challinor and R. Maartens, Phys. Rep. 465, 61 (2008).

Slow decay of magnetic fields in open Friedmann universes
J.D. Barrow and C.G. Tsagas, Phys. Rev. D 77, 107302 (2008).

Newtonian nonlinear hydrodynamics and magnetohydrodynamics
N.K. Spyrou and C.G. Tsagas, Mon. Not. R. Astron. Soc. 388, 187 (2008).

Generalised Ohm's law for relativistic plasmas
A. Kandus and C.G. Tsagas, Mon. Not. R. Astron. Soc. 385, 883 (2008).

Cosmology with inhomogeneous magnetic fields
J.D. Barrow, R. Maartens and C.G. Tsagas, Phys. Rep. 449, 131 (2007).

Comment on ``Primordial magnetic seed amplification by gravitational waves''
C.G. Tsagas, Phys. Rev. D 75, 087901 (2007).

Averaging anisotropic cosmologies
J.D. Barrow and C.G. Tsagas, Class. Quantum Grav. 24, 1023 (2007).

Cosmology in three dimensions: steps towards the general solution

J.D. Barrow, D.J. Shaw and C.G. Tsagas, Class. Quantum Grav. 23, 5291 (2006).

Magnetic tension and gravitational collapse
C.G. Tsagas, Class. Quantum Grav. 23, 4323 (2006).

Magnetised Tolman-Bondi collapse
C. Germani and C.G. Tsagas, Phys. Rev. D 73, 064010 (2006).

Resonant amplification of magnetic seed fields by gravitational waves in the early universe
C.G. Tsagas, Phys. Rev. D 72, 123509 (2005).

Superadiabatic-type magnetic amplification in conventional cosmology
C.G. Tsagas and A. Kandus, Phys. Rev. D 71, 123506 (2005).

New isotropic and anisotropic sudden singularities
J.D. Barrow and C.G. Tsagas, Class. Quantum Grav. 22, 1563 (2005).

Galaxy formation and cosmic-ray acceleration in a magnetised universe
L. Vlahos, C.G. Tsagas and D. Papadopoulos, Astrophys. J. Lett. 629, L9 (2005).

Structure and stability of the Lukash plane-wave spacetime
J.D. Barrow and C.G. Tsagas, Class. Quantum Grav. 22, 825 (2005).

Electromagnetic fields in curved spacetimes
C.G. Tsagas, Class. Quantum Grav. 22, 393 (2005).

Covariant approach to the conformal dynamical equivalence in astrophysics
N.K. Spyrou and C.G. Tsagas, Class. Quantum Grav. 21, 2435 (2004).

Gödel brane
J.D. Barrow and C.G. Tsagas, Phys. Rev. D 69, 064007 (2004).

Dynamics and stability of the Gödel universe
J.D. Barrow and C.G. Tsagas, Class. Quantum Grav. 21, 1773 (2004).

The emergent universe: an explicit construction
G.F.R. Ellis, J. Murugan and C.G. Tsagas, Class. Quantum Grav. 21, 233 (2004).

On the stability of the Einstein static universe

J.D. Barrow, G.F.R. Ellis, R. Maartens and C.G. Tsagas, Class. Quantum Grav. 20, L155 (2003).

Charged multifluids in general relativity
M. Marklund, P.K.S. Dunsby, G. Betschart, M. Servin and C.G. Tsagas, Class. Quantum Grav. 20, 1823 (2003).

CMB limits on large-scale magnetic fields in an inhomogeneous universe
C.A. Clarkson, A.A. Coley, R. Maartens and C.G. Tsagas, Class. Quantum Grav. 20, 1519 (2003).

Gravitational wave amplification of seed magnetic fields
C.G. Tsagas, P.K.S. Dunsby and M. Marklund, Phys. Lett. B 561, 17 (2003).

Magnetic field amplification in cold dark matter anisotropic collapse
M. Bruni, R. Maartens and C.G. Tsagas, Mon. Not. R. Astron. Soc. 338, 785 (2003).

Relativistic approach to nonlinear peculiar velocities and the Zeldovich approximation
G.F.R. Ellis and C.G. Tsagas, Phys. Rev. D 66, 124015 (2002).

Gravitational waves and cosmic magnetism: a cosmological approach
C.G. Tsagas, Class. Quantum Grav. 19, 3709 (2002).

Magnetic tension and the geometry of the universe
C.G. Tsagas, Phys. Rev. Lett. 86, 5421 (2001).

Magnetised gravitational waves
R. Maartens, C.G. Tsagas and C. Ungarelli, Phys. Rev. D 63, 123507 (2001).

Cosmic magnetism, curvature, and the expansion dynamics
D.R. Matravers and C.G. Tsagas, Phys. Rev. D 62, 103519 (2000).

Cosmological perturbations on a magnetised Bianchi I background
C.G. Tsagas and R. Maartens, Class. Quantum Grav. 17, 2215 (2000).

Magnetised cosmological perturbations
C.G. Tsagas and R. Maartens, Phys. Rev. D 61, 083519 (2000).

Gauge-invariant magnetic perturbations in perfect-fluid cosmologies
C.G. Tsagas and J.D. Barrow, Class. Quantum Grav. 15, 3523 (1998).

A gauge-invariant analysis of magnetic fields in general-relativistic cosmology
C.G. Tsagas and J.D. Barrow, Class. Quantum Grav. 14, 2539 (1997).

NASA ADS

SPIRES

Selected Special Issues, Conferences, Workshops & Schools

(Invited Papers, Reviews & Lectures)

Relativistic magnetised perturbations: magnetic pressure vs magnetic tension
D. Tseneklidou, C.G. Tsagas and J.D. Barrow, in Magnetic Fields at Cosmological Scales.
Class. Quantum Grav. (Focus) 35, 124001 (2018).

On the magnetic evolution in Friedmann universes and the question of cosmic magnetogenesis
C.G. Tsagas, in Revealing the Symmetries of the Universe: Dark Energy, Inflation and Modified Gravity.
Symmetry 8, 122 (2016).

Relaxing the limits on inflationary magnetogenesis II
C.G. Tsagas, in Proceedings of the 28th Texas Symposium on Relativistic Astrophysics.
Geneva, Swintzerland, 2015.

Linear cosmological perturbation theory
C.G. Tsagas, in Structure Formation in an Expanding Universe (EDUFES, Vitoria, Brazil, 2014) p. 43.
1st Jose Plinio Baptista School of Cosmology, Ubu, Espirito Santo, Brazil, 2012.

The mystery of cosmic magnetogenesis
C.G. Tsagas, Highlights of Astronomy 16, 408 (CUP, Cambridge, 2014).
XXVIII IAU General Assembly, Beijing, China , 2012.

The first magnetic fields
L.M. Widrow, D. Ryu, D.R.G., Schleicher, K. Subramanian, C.G. Tsagas and R.A. Treumann,
in Large-Scale Magnetic Fields in the Universe, Space Sci. Rev. 166, 37 (Springer, New York, 2013).
ISSI Workshop, Bern, Switzerland, 2010.

Magneric fields in the large-scale structure of the universe
D. Ryu, D.R.G. Schleicher, R.A. Treumann, C.G. Tsagas and L.M. Widrow,
in Large-Scale Magnetic Fields in the Universe, Space Sci. Rev. 166, 1 (Springer, New York, 2013).
ISSI Workshop, Bern, Switzerland, 2010.

Large-scale magnetic fields in cosmology
C.G. Tsagas, Plasma Phys. Contol. Fusion 51, 124013 (IOP Publ., Bristol, UK, 2009).
36 EPS Conference on Plasma Physics, Sofia, Bulgaria, 2009.

Cosmological perturbations
C.G. Tsagas, in Cosmological Crossroads, Lect. Notes Phys. 592, 223 (Springer-Verlag, Berlin, 2002).
1st Aegean Summer School, Samos, Greece, 2001.