Dr Istvan Ballai

School of Mathematical and Physical Sciences

Senior Lecturer in Applied Mathematics

i.ballai@sheffield.ac.uk
+44 114 222 3833
H9, Hicks Building

Full contact details

Dr Istvan Ballai
School of Mathematical and Physical Sciences
H9
Hicks Building
Hounsfield Road
Sheffield
S3 7RH
Research interests

Dr. Istvan Ballai's main research interest is in linear and nonlinear MagnetoHydroDynamics (MHD) waves occurring in solar and interplanetary plasmas.

Waves can carry energy and momentum; when transferred to inhomogeneous plasmas they can heat or accelerate the plasma therefore MHD waves may play an important role in explaining the observed high temperatures in the solar corona. Waves can transport information about the environment in which they propagate, so they can serve as a perfect tool for plasma diagnostics. In this context I use local and global coronal waves to find average values for magnetic field and transport coefficients in the solar corona. 

When the temperature of the plasma is not high enough to ensure a full ionisation, the plasma becomes partially ionised with particles of different species colliding and modifying each other momentum and energy. My research focusses on the properties of linear and nonlinear waves in partially ionised plasmas, as well the stability of dynamical changes occurring in these environments.

Publications

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All publications

Journal articles

  • McMurdo M, Ballai I, Verth G & Fedun V (2025) . The Astrophysical Journal, 988(1).
  • Skirvin SJ, Fedun V, Verth G & Ballai I (2025) . The Astrophysical Journal, 988(1).
  • Góra-Gálik B, Forgács-Dajka E & Ballai I (2025) . Universe, 11(6).
  • Lennard MG, Silva SSA, Tremblay B, Ramos AA, Verth G, Ballai I, Iijima H, Hotta H, Rempel M, Park S-H & Fedun V (2025) . Monthly Notices of the Royal Astronomical Society, 539(3), 2498-2512.
  • Silva SSA, Verth G, Ballai I, Rempel EL, Shelyag S, Schiavo LACA, Gomes TFP & Fedun V (2024) . The Astrophysical Journal, 975(1).
  • Schiavo LACA, Gordovskyy M, Browning PK, de Souza e Almeida Silva S, Verth G, Ballai I, Shelyag S, Ruzheinikov SN, McLaughlin JA & Fedun V (2024) . The Astrophysical Journal, 975(1).
  • Kozak L, Ballai I, Fedun V, Kronberg EA, Bloecker A & Petrenko B (2024) . Journal of Atmospheric and Solar-Terrestrial Physics, 265.
  • Ballai I, Asiri F, Fedun V, Verth G, Forgács-Dajka E & Albidah AB (2024) . Universe, 10(8).
  • Jafarzadeh S, Schiavo LACA, Fedun V, Solanki SK, Stangalini M, Calchetti D, Verth G, Jess DB, Grant SDT, Ballai I , Gafeira R et al (2024) . Astronomy & Astrophysics, 688.
  • Ballai I, Forgács-Dajka E & McMurdo M (2024) . Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 382(2272).
  • Asiri F, Ballai I, Fedun V, Verth G, Ruzheinikov SN & Albidah AB (2024) . Monthly Notices of the Royal Astronomical Society, 529(1), 748-760.
  • Silva SSA, Verth G, Rempel EL, Ballai I, Jafarzadeh S & Fedun V (2024) . The Astrophysical Journal, 963(1).
  • McMurdo M, Ballai I, Verth G, Alharbi A & Fedun V (2023) . The Astrophysical Journal, 958(1).
  • Kozak L, Kronberg EA, Petrenko B, Blöcker A, Akhmetshyn R, Ballai I & Fedun V (2023) . Frontiers in Astronomy and Space Sciences, 10.
  • Cheremnykh O, Fedorenko A, Voitsekhovska A, Selivanov Y, Ballai I, Verth G & Fedun V (2023) . Advances in Space Research, 72(11), 4825-4835.
  • Albidah AB, Fedun V, Aldhafeeri AA, Ballai I, Jess DB, Brevis W, Higham J, Stangalini M, Silva SSA, MacBride CD & Verth G (2023) . The Astrophysical Journal, 954(1).
  • Caspi A, Seaton D, Casini R, Downs C, Gibson S, Gilbert H, Glesener L, Guidoni S, Hughes JM, McKenzie D , Plowman J et al (2023) . Bulletin of the American Astronomical Society, 55(3).
  • Silva SSA, Lennard M, Verth G, Ballai I, Rempel EL, Warnecke J, Iijima H, Hotta H, Park S-H, Donea AC , Kusano K et al (2023) . The Astrophysical Journal Letters, 948(2).
  • Kontar E & Ballai I (2022) . Advances in Space Research.
  • Aldhafeeri AA, Verth G, Fedun V, Lennard M & Ballai I (2022) . The Astrophysical Journal, 938(1).
  • Skirvin S, Verth G, González-Avilés JJ, Shelyag S, Sharma R, Guzmán FS, Ballai I, Scullion E, Silva SSA & Fedun V (2022) . Advances in Space Research.
  • Aldhafeeri A, Fedun V, Ballai I & Verth G (2022) . EGU General Assembly 2022.
  • Aljohani Y, Fedun V, Ballai I, Silva SSA, Shelyag S & Verth G (2022) . The Astrophysical Journal, 928(1).
  • Albidah AB, Fedun V, Aldhafeeri AA, Ballai I, Brevis W, Jess DB, Higham J, Stangalini M, Silva SSA & Verth G (2022) . The Astrophysical Journal, 927(2).
  • Silva SSA, Murabito M, Jafarzadeh S, Stangliani M, Verth G, Ballai I & Fedun V (2022) . The Astrophysical Journal, 927(2).
  • Alharbi A, Ballai I, Fedun V & Verth G (2022) . Monthly Notices of the Royal Astronomical Society, 511(4), 5274-5286.
  • Petrenko B, Kozak L, Kronberg E & Ballai I (2022) . Bulletin of Taras Shevchenko National University of Kyiv. Astronomy(66), 20-25.
  • Onishchenko O, Fedun V, Ballai I, Kryshtal A & Verth G (2021) . Fluids, 6(12).
  • Forgács-Dajka E, Dobos L & Ballai I (2021) . Astronomy and Astrophysics, 653.
  • Rast MP, Bello González N, Bellot Rubio L, Cao W, Cauzzi G, DeLuca E, De Pontieu B, Fletcher L, Gibson SE, Judge PG , Katsukawa Y et al (2021) . Solar Physics, 296(4).
  • Albidah AB, Brevis W, Fedun V, Ballai I, Jess DB, Stangalini M, Higham J & Verth G (2021) . Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 379(2190).
  • Alharbi A, Ballai I, Fedun V & Verth G (2020) . Monthly Notices of the Royal Astronomical Society, 501(2), 1940-1950.
  • Kryshtal A, Voitsekhovska A, Cheremnykh O, Ballai I, Verth G & Fedun V (2020) . Solar Physics, 295(12).
  • Ballai I (2020) . Astronomy & Astrophysics, 635.
  • Vickers E, Ballai I & Erdélyi R (2020) . Astronomy & Astrophysics, 634.
  • Ballai I (2019) . Frontiers in Astronomy and Space Sciences, 6.
  • Ballai I, Forgacs-Dajka E & Marcu A (2019) . Advances in Space Research, 63(4), 1472-1482.
  • Ruderman MS, Vickers E, Ballai I & Erdelyi R (2018) . Physics of Plasmas, 25(12).
  • Vickers E, Ballai I & Erdélyi R (2018) . Solar Physics, 293.
  • Mather J, Ballai I & Erdélyi R (2018) . Astronomy and Astrophysics, 610.
  • Ruderman MS, Ballai I, Khomenko E & Collados M (2018) . Astronomy and Astrophysics, 609.
  • Ballai I, Pinter B, Oliver R & Alexandrou M (2017) . Astronomy & Astrophysics.
  • Gyenge N, Ballai I & Baranyi T (2016) . Monthly Notices of the Royal Astronomical Society, 459(4), 3532-3539.
  • Ballai I, Oliver R & Alexandrou M (2015) . Astronomy and Astrophysics, 577.
  • Balázs LG, Gyenge N, Korsós MB, Baranyi T, Forgács-Dajka E & Ballai I (2014) Statistical relationship between the succeeding solar flares detected by the RHESSI satellite. MNRAS, 441, 1157-1165.
  • Murawski K, Ballai I, Srivastava AK & Lee D (2013) Three-dimensional numerical simulation of magnetohydrodynamic-gravity waves and vortices in the solar atmosphere.
  • Orza B & Ballai I (2013) . Astronomische Nachrichten, 334(9), 948-951.
  • Pardi A-L, Ballai I, Marcu A & Orza B (2013) Sausage Mode Propagation in a Thick Magnetic Flux Tube. 2013SoPh..tmp..229P.
  • Ballai I & Orza B (2012) Transverse kink oscillations of expanding coronal loops.
  • Orza B, Ballai I, Jain R & Murawski K (2011) The effect of the environment on the P1/P2 period ratio for kink oscillations of coronal loops.
  • Ballai I, Jess DB & Douglas M (2011) TRACE Observations of Driven Loop Oscillations.
  • Ballai I, Forgacs-Dajka E & Douglas M (2011) . ASTRON ASTROPHYS, 527.
  • Ballai I & Ruderman M (2010) Nonlinear effects in resonant layers in solar and space plasmas.
  • Ballai I & Forgács-Dajka E (2010) . Journal of Physics Conference Series, 218(1).
  • Clack CTM, Ballai I & Douglas M (2010) Resonant Absorption of Fast Magnetoacoustic Waves due to Coupling into the Slow and Alfven Continua in the Solar Atmosphere. Solar Physics 06/2010.
  • Terradas J, Goossens M & Ballai I (2009) The effect of longitudinal flow on resonantly damped kink oscillations.
  • Clack CTM & Ballai I (2009) . PHYS PLASMAS, 16(7).
  • Clack CTM & Ballai I (2009) . PHYS PLASMAS, 16(4).
  • Clack CTM, Ballai I & Ruderman MS (2009) . ASTRON ASTROPHYS, 494(1), 317-327.
  • Mocanu G, Marcu A, Ballai I & Orza B (2008) . ASTRON NACHR, 329(8), 780-785.
  • Clack CTM & Ballai I (2008) . PHYS PLASMAS, 15(8).
  • Ballai I, Douglas M & Marcu A (2008) . ASTRON ASTROPHYS, 488(3), 1125-1132.
  • Ballai I (2007) . Aip Conference Proceedings, 934, 44-53.
  • Douglas M & Ballai I (2007) MHD waves at a spherical interface modelling EIT waves. ASTRON NACHR, 328(8), 769-772.
  • Ballai I, Forgacs-Dajka E & Marcu A (2007) Dispersive shock waves in the solar wind. ASTRON NACHR, 328(8), 734-737.
  • Forgacs-Dajka E, Ballai I & van Driel-Gesztelyi L (2007) Untitled. ASTRON NACHR, 328(8), 725-725.
  • Erdelyi R & Ballai I (2007) Heating of the solar and stellar coronae: a review. ASTRON NACHR, 328(8), 726-733.
  • Marcu A, Ballai I & Orza B (2007) . Proceedings of the International Astronomical Union, 3(S247), 320-323.
  • Douglas M & Ballai I (2007) . Proceedings of the International Astronomical Union, 3(S247), 251-254.
  • Ballai I & Douglas M (2007) . Proceedings of the International Astronomical Union, 3(S247), 243-250.
  • Marcu A & Ballai I (2007) Thermosolutal stability of a two-component rotating plasma with finite Larmor radius. PROC ROM ACAD SER A, 8(2), 111-120.
  • Ballai I (2006) . Proceedings of the International Astronomical Union, 2(233), 132-133.
  • Ballai I, Erdelyi R & Hargreaves J (2006) . PHYS PLASMAS, 13(4).
  • Marcu A, Ballai I & Pinter B (2006) . ASTRON ASTROPHYS, 449(3), 1193-1202.
  • Cally PS, De Moortel I & Ballai I (2006) Untitled. PHILOS T ROY SOC A, 364(1839), 471-472.
  • Marcu A & Ballai I (2006) The damping of slow magnetoacustic waves in coronal loops. J OPTOELECTRON ADV M, 8(4), 1562-1564.
  • De Moortel I, Cally PS & Ballai I (2006) . Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences, 364(1839), 461-472.
  • Ballai I, Erdelyi R & Pinter B (2005) On the nature of coronal EIT waves. ASTROPHYS J, 633(2), L145-L148.
  • Ballai I & Chaplin B (2005) Seismology of the sun: From the inner core to the corona. Observatory, 125(1187), 224-227.
  • Chaplin WJ & Ballai I (2005) The sound of the Sun. ASTRON GEOPHYS, 46(4), 27-30.
  • Ballai I (2004) Damping of compressional waves in coronal prominences. European Space Agency Special Publication ESA SP(547), 211-214.
  • Ballai I & Erdélyi R (2004) Damping of coronal EIT waves as a tool for plasma diagnostics. European Space Agency Special Publication ESA SP(547), 433-440.
  • Ballai I (2004) . Astronomy and Geophysics, 45(4), 4.44-4.45.
  • Ballai I & Marcu A (2004) . ASTRON ASTROPHYS, 415(2), 691-703.
  • Ballai I (2003) . ASTRON ASTROPHYS, 410(2), L17-L19.
  • Terra-Homem M, Erdelyi R & Ballai I (2003) Linear and non-linear MHD wave propagation in steady-state magnetic cylinders. SOL PHYS, 217(2), 199-223.
  • Ballai I, Thelen JC & Roberts B (2003) . ASTRON ASTROPHYS, 404(2), 701-707.
  • Ballai I, Erdelyi R & Roberts B (2002) Ducted compressional waves in the magnetosphere in the double-polytropic approximation. ANN GEOPHYS-GERMANY, 20(10), 1553-1558.
  • Ballai I & Zhugzhda YD (2002) . PHYS PLASMAS, 9(10), 4280-4284.
  • Ballai I & Erdelyi R (2002) . J PLASMA PHYS, 67, 79-97.
  • Ballai I, Erdelyi R, Voitenko Y & Goossens M (2002) . PHYS PLASMAS, 9(6), 2593-2603.
  • Erdelyi R & Ballai I (2002) Dynamics of nonlinear resonant slow MHD waves in twisted flux tubes. NONLINEAR PROC GEOPH, 9(2), 79-86.
  • Erdelyi R, Ballai I & Goossens M (2001) Nonlinear resonant absorption of fast magnetoacoustic waves due to coupling into slow continue in the solar atmosphere. ASTRON ASTROPHYS, 368(2), 662-675.
  • Ballai I, Erdelyi R & Goossens M (2000) Nonlinear theory of non-axisymmetric resonant slow waves in straight magnetic flux tubes. J PLASMA PHYS, 64, 579-599.
  • Ballai I, Erdelyi R & Goossens M (2000) Linear and nonlinear resonant interaction of sound waves in dissipative layers. J PLASMA PHYS, 64, 235-247.
  • Erdelyi R & Ballai I (1999) Resonant absorption of nonlinear slow MHD waves in isotropic steady plasmas - II. Application: Resonant acoustic waves. SOL PHYS, 186(1-2), 67-97.
  • Ballai I, Erdelyi R & Ruderman MS (1998) Interaction of sound waves with slow dissipative layers in anisotropic plasmas in the approximation of weak nonlinearity. PHYS PLASMAS, 5(6), 2264-2273.
  • Ballai I, Ruderman MS & Erdelyi R (1998) Nonlinear theory of slow dissipative layers in anisotropic plasmas. PHYS PLASMAS, 5(1), 252-260.
  • Ballai I & Erdelyi R (1998) Resonant absorption of nonlinear slow MHD waves in isotropic steady plasmas - I. Theory. SOL PHYS, 180(1-2), 65-79.

Conference proceedings

  • Kozak L, Petrenko B, Kronberg E, Akhmetshyn R & Ballai I (2023) . EGU General Assembly 2023. Vienna, Austria, 23 April 2023 - 23 April 2023.
  • Cho Y-H, Lim J, Kalra A, Nair V, Rontogiannis G, Seniuc I-V, Schiona A, Narayanankutty G, Ioannou K, Lennard MG , Appleby B et al (2019) Sheffield University Nova Rocket Innovative Design Engineering (SUNRIDE). 24th ESA Symposium on European Rocket and Balloon Programmes and Related Research Proceedings (pp 122-127). Noordwijk, The Netherlands, 16 June 2019 - 16 June 2019.
  • Marcu A & Ballai I (2007) Thermally damped waves in the solar corona. FLOWS, BOUNDARIES, INTERACTIONS, Vol. 934 (pp 64-70)
  • Ballai I (2007) MHD waves in stratified and dissipative plasmas. Fifty Years of Romanian Astrophysics, Vol. 895 (pp 141-146)
  • Ballai I (2007) . SOLAR PHYSICS, Vol. 246(1) (pp 177-185)
  • Ballai I (2006) . First International Workshop and Summer School on Plasma Physics, Vol. 44 (pp 20-29)
  • Ballai I, Thelen JC & Roberts B (2002) Wave damping in hall plasmas - Application to the solar wind. SOLMAG 2002: PROCEEDINGS OF THE MAGNETIC COUPLING OF THE SOLAR ATMOSPHERE EUROCONFERENCE AND IAU COLLOQUIUM 188, Vol. 505 (pp 345-348)
  • Ballai I, Erdelyi R & Goossens M (2000) Linear and nonlinear waves in dilute plasmas. WAVES IN DUSTY, SOLAR, AND SPACE PLASMAS, Vol. 537 (pp 152-159)
  • Ballai I, Erdelyi R & Goossens M (2000) Absorption of fast magnetosonic waves in the solar atmosphere in the limit of weak nonlinearity. WAVES IN DUSTY, SOLAR, AND SPACE PLASMAS, Vol. 537 (pp 144-151)
  • Erdelyi R, Ballai I & Ruderman MS (1999) Strongly nonlinear resonant MHD waves in the steady solar magnetic canopy. 9TH EUROPEAN MEETING ON SOLAR PHYSICS: MAGNETIC FIELDS AND SOLAR PROCESSES, VOLS 1 AND 2, Vol. 448 (pp 263-267)
  • Ballai I & Erdelyi R (1999) Nonlinear resonant MHD waves in the atmosphere of the sun. 8TH SOHO WORKSHOP: PLASMA DYNAMICS AND DIAGNOSTICS IN THE SOLAR TRANSITION REGION AND CORONA, PROCEEDINGS, Vol. 446 (pp 155-160)

Preprints

  • Silva SSA, Rempel E, Verth G, Ballai I & Fedun V (2025) , arXiv.
  • Silva SSA, Dakanalis I, Schiavo LACA, Tziotziou K, Ballai I, Jafarzadeh S, Pereira TMD, Tsiropoula G, Verth G, Esnaola IA , McLaughlin JA et al (2025) , arXiv.
  • Silva SSA, Gonzalez-Aviles JJ, Riley P, Ben-Nun M, Rempel EL, Batista LFG, Verth G, Ballai I, Lin C-H, Schiavo LACA & Fedun V (2025) , arXiv.
  • McMurdo M, Ballai I, Verth G & Fedun V (2025) , arXiv.
  • Skirvin S, Fedun V, Verth G & Ballai I (2025) , arXiv.
  • Schiavo LACA, Gordovskyy M, Browning PK, Silva SSA, Verth G, Ballai I, Shelyag S, Ruzheinikov SN, McLaughlin JA & Fedun V (2024) , arXiv.
  • Jafarzadeh S, Schiavo LAC, Fedun V, Solanki SK, Stangalini M, Calchetti D, Verth G, Jess DB, Grant SDT, Ballai I , Gafeira R et al (2024) , arXiv.
  • McMurdo M, Ballai I, Verth G, Alharbi A & Fedun V (2023) , arXiv.
  • O. C, A. F, A. V, Yu. S, I. B, G. V & V F (2023) , arXiv.
  • Albidah AB, Fedun V, Aldhafeeri AA, Ballai I, Jess DB, Brevis W, Higham J, Stangalini M, Silva SSA, MacBride CD & Verth G (2023) , arXiv.
  • Aldhafeeri A, Verth G, Fedun V, Lennard M & Ballai I (2022) , arXiv.
  • Skirvin S, Verth G, González-Avilés JJ, Shelyag S, Sharma R, Guzmán F, Ballai I, Scullion E, Silva SSA & Fedun V (2022) , arXiv.
  • Silva SSA, Murabito M, Jafarzadeh S, Stangliani M, Verth G, Ballai I & Fedun V (2022) , arXiv.
  • Aljohani Y, Fedun V, Ballai I, Silva SSA, Shelyag S & Verth G (2022) , arXiv.
  • Alharbi A, Ballai I, Fedun V & Verth G (2022) , arXiv.
  • Albidah AB, Fedun V, Aldhafeeri AA, Ballai I, Brevis W, Jess DB, Higham J, Stangalini M, Silva SSA & Verth G (2022) , arXiv.
  • Forgács-Dajka E, Dobos L & Ballai I (2021) , arXiv.
  • Alharbi A, Ballai I, Fedun V & Verth G (2020) , arXiv.
  • Albidah AB, Brevis W, Fedun V, Ballai I, Jess DB, Stangalini M, Higham J & Verth G (2020) , arXiv.
  • Rast MP, González NB, Rubio LB, Cao W, Cauzzi G, DeLuca E, De Pontieu B, Fletcher L, Gibson SE, Judge PG , Katsukawa Y et al (2020) , arXiv.
  • Ballai I (2020) , arXiv.
  • Vickers E, Ballai I & Erdélyi R (2019) , arXiv.
  • Ballai I, Forgacs-Dajka E & Marcu A (2018) , arXiv.
  • Vickers E, Ballai I & Erdélyi R (2018) , arXiv.
  • Mather JF, Ballai I & Erdelyi R (2017) , arXiv.
  • Ballai I, Pinter B, Oliver R & Alexandrou M (2017) , arXiv.
  • Gyenge N, Ballai I & Baranyi T (2016) , arXiv.
  • Ballai I, Oliver R & Alexandrou M (2015) , arXiv.
  • Balázs LG, Gyenge N, Korsós MB, Baranyi T, Forgács-Dajka E & Ballai I (2014) , arXiv.
  • Pardi A-L, Ballai I, Marcu A & Orza B (2013) , arXiv.
  • Murawski K, Ballai I, Srivastava AK & Lee D (2013) , arXiv.
  • Ballai I & Orza B (2012) , arXiv.
  • Orza B, Ballai I, Jain R & Murawski K (2011) , arXiv.
  • Ballai I, Jess DB & Douglas M (2011) , arXiv.
  • Ballai I & Ruderman M (2010) , arXiv.
  • Clack CTM, Ballai I & Douglas M (2010) , arXiv.
  • Terradas J, Goossens M & Ballai I (2009) , arXiv.
  • Clack CTM & Ballai I (2009) , arXiv.
  • Clack C & Ballai I (2009) , arXiv.
  • Clack CTM, Ballai I & Ruderman MS (2008) , arXiv.
  • Clack C & Ballai I (2008) , arXiv.
  • Ballai I, Douglas M & Marcu A (2008) , arXiv.
  • Ballai I (2007) , arXiv.
Research group

Grants

Past grants, as Principal Investigator
Instabilities in partially ionized prominence plasmas Leverhulme
Damping of Forced Oscillations in Coronal Loops RS
Conference Attendance RS
Global Coronal Seismology Using SOHO/EIT Observations Nuffield

Past grants, as Coinvestigator
Application to STFC for Consolidated Grant Support for the Solar Physics and Space Plasma Research Centre (SP2RC) STFC
Consolidated Grant Support for the Solar Physics and Space Plasma Research Centre (SP2RC) STFC
Heating and Magneto-Seismology of the Solar Atmosphere STFC
Teaching interests
  • Differential and difference equations
  • Complex Analysis
  • Numerical methods