Summary
In this project groundbreaking methodology is developed for creating virtual seismic sources (earthquakes or seismic vibrators) and virtual seismometers anywhere in the subsurface, from seismic reflection measurements carried out at the surface of the earth. This is called Virtual Seismology (VS). VS accurately mimics the responses to actual earthquakes that would be recorded by actual buried seismometers, including all multiple scattering effects.
In particular VS will be developed for:
(1) Investigating induced-earthquake problems. (a) High-density multi-component seismic acquisition methodology will be developed (Distributed Acoustic Sensing: DAS), using the latest technology of controllable seismic vibrators and seismic sensing with fibre-optic cables, and it will be applied in an actual induced-earthquake sensitive area. (b) These data will be used to create virtual sources and receivers in the subsurface to characterize induced earthquakes, quantify the ground motion of actual and possible future earthquakes, and monitor the geomechanical state of the area over time.
(2) Imaging and monitoring subsurface fluid flow. Highly repeatable VS methodology will be developed for time-lapse 3D reflection data to monitor fluid-flow processes in the subsurface with excellent spatial and temporal resolution.
Learn more about this from this E-lecture: Virtual Seismology: monitoring the subsurface with virtual sources and receivers (2019). For some more background go this E-lecture: Data-driven Green's function retrieval from reflection data (2015).
News item at Cordis: Making virtual seismology a reality
Brackenhoff, J., Thorbecke, J., and Wapenaar, K., 2019, Monitoring of induced distributed double-couple sources using Marchenko-based virtual receivers: Solid Earth, Vol. 10, 1301-1319. pdf-file
(2) Meles, G.A., Wapenaar, K., and Thorbecke, J., 2018, Virtual plane-wave imaging via Marchenko redatuming: Geoph. J. Int., Vol. 214, 508-519. pdf-file
(3) Wapenaar, K., Brackenhoff, J., Thorbecke, J., van der Neut, J., Slob, E., and Verschuur, E., 2018, Virtual acoustics in inhomogeneous media with single-sided access: Scientific Reports, Vol. 8, 2497. pdf-file Movies: Fig1a, Fig1b, Fig1c, Fig1d, Fig3, Fig4. The paper can be accessed via the Scientific Reports website of Nature: html-link
(4) Staring, M., Pereira, R., Douma, H., van der Neut, J., and Wapenaar, K., 2018, Source-receiver Marchenko redatuming on field data using an adaptive double-focusing method: Geophysics, Vol. 83 (6), S579-S590. pdf-file
(5) Wapenaar, K., 2019, Unified matrix-vector wave equation, reciprocity and representations: Geoph. J. Int., Vol. 216, 560-583. pdf-file
(6) Wapenaar, K., and Reinicke, C., 2019, An acoustic imaging method for layered non-reciprocal media: EPL (Europhysics Letters), Vol. 125, 34003. pdf-file
(7) Reinicke, C., and Wapenaar, K., 2019, Elastodynamic single-sided homogeneous Green's function representation: Theory and numerical examples: Wave Motion, Vol. 89, 245-264. pdf-file Online paper html-link
(8) Wapenaar, K., Brackenhoff, J., and Thorbecke, J., 2019, Green's theorem in seismic imaging across the scales: Solid Earth, Vol. 10, 517-536. pdf-file Online paper html-link
(9) Wapenaar, K., and Reinicke, C., 2019, Unified wave field retrieval and imaging method for inhomogeneous non-reciprocal media: J. Acoust. Soc. Am., Vol. 146 (1), 810-825. pdf-file Copyright (2019) Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America. The article appeared in JASA and may be found at doi.org/10.1121/1.5114912.
(10) Meles, G.A., van der Neut, J., van Dongen, K.W.A., and Wapenaar, K., 2018, Wavefield finite time focusing with reduced spatial exposure: J. Acoust. Soc. Am., Vol. 145 (6), 3521-3530. pdf-file Copyright (2019) Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America. The article appeared in JASA and may be found at doi.org/10.1121/1.5110716.
(11) Brackenhoff, J., Thorbecke, J., and Wapenaar, K., 2019, Monitoring of induced distributed double-couple sources using Marchenko-based virtual receivers: Solid Earth, Vol. 10, 1301-1319. pdf-file Online paper html-link
(12) Brackenhoff, J., Thorbecke, J., and Wapenaar, K., 2019, Virtual sources and receivers in the real Earth: Considerations for practical applications: Journal of Geophysical Research - Solid Earth, Vol. 124, 11,802-11,821. pdf-file
(13) Zhang, L., Thorbecke, J., Wapenaar, K., and Slob, E., 2019, Transmission compensated primary reflection retrieval in the data domain and consequences for imaging: Geophysics, Vol. 84 (4), Q27-Q36. pdf-file
(14) Sripanich, Y., Vasconcelos, I., and Wapenaar, K., 2019, Velocity-independent Marchenko focusing in time- and depth-imaging domains for media with mild lateral heterogeneity: Geophysics, Vol. 84 (6), Q57-Q72. pdf-file
(15) Zhang, L., Thorbecke, J., Wapenaar, K., and Slob, E., 2019, Data-driven internal multiple elimination and its consequences for imaging: A comparison of strategies: Geophysics, Vol. 84 (5), S365-S372. pdf-file Bright spots column pdf-file.
(16) Slob, E., Wapenaar, K., and Treitel, S., 2020, Tutorial: unified 1D inversion of the acoustic reflection response: Geophysical Prospecting, Vol. 68, 1425-1442. pdf-file
(17) Wapenaar, K., and van IJsseldijk, J., 2020, Discrete representations for Marchenko imaging of imperfectly sampled data: Geophysics, Vol. 85 (2), A1-A5. pdf-file
(18) Wapenaar, K., 2020, Reciprocity and representation theorems for flux- and field-normalised decomposed wave fields: Advances in Mathematical Physics, Vol. 2020, 9540135. pdf-file
(19) Meles, G.A., Zhang, L., Thorbecke, J., Wapenaar, K., and Slob, E., 2020, Data-driven retrieval of primary plane-wave responses: Geophysical Prospecting, Vol. 68, 1834-1846. pdf-file.
(20) Reinicke, C., Meles, G.A., and Wapenaar, K., 2018, Elastodynamic plane wave Marchenko redatuming: Theory and examples, 80th annual EAGE meeting, Copenhagen, Th-A10-01, pdf
(21) Staring, M., van der Neut, J., and Wapenaar, K., 2018, Marchenko redatuming by adaptive double-focusing on 2D and 3D field data of the Santos basin (invited), 88th annual SEG meeting, Anaheim, Workshop W-4: The business value of multiple identification and removal - Status, challenges and road ahead, 5449-5453, pdf
(22) Wapenaar, K., Brackenhoff, J., and Thorbecke, J., 2018, Marchenko method for monitoring induced seismicity with virtual receivers, 88th annual SEG meeting, Anaheim, 5037-5042, pdf
(23) Reinicke, C., Dukalski, M., and Wapenaar, K., 2019, Tackling different velocity borne challenges of the elastodynamic Marchenko method, 81rst annual EAGE meeting, London, Th-R04-04, pdf
(24) Brackenhoff, J., Thorbecke, J., and Wapenaar, K., 2019, Monitoring induced distributed double-couple sources using Marchenko-based virtual receivers, 81rst annual EAGE meeting, London, Th-R04-07, pdf
(25) Staring, M., and Wapenaar, K., 2019, Interbed demultiple using Marchenko redatuming on 3D field data of the Santos basin, The sixteenth international congress of the Brazilian Geophysical Society, Rio de Janeiro, SBGf, (6 pages), pdf-file
(26) Wapenaar, K., and van IJsseldijk, J., 2019, Representations for the Marchenko method for imperfectly sampled data, 89th annual SEG meeting, San Antonio, 4545-4549, pdf-file
(27) Meles, G.A., van der Neut, J., van Dongen, K.W.A., and Wapenaar, K., 2019, Wavefield focusing with reduced cranial invasiveness, Proceedings of the IEEE IUS 2019, Glasgow, WeH6.2, pdf-file
(28) Vardon, P.J., Bruhn, D.F., Steiginga, A., Cox, B., Abels, H., Barnhoorn, A., Drijkoningen, G., Slob, E., and Wapenaar, K., 2020, A geothermal well doublet for research and heat supply of the TU Delft campus, Proceedings World Geothermal Congress 2020, Reykjavik, Iceland, April 26 - May 2, 2020 (postponed until 2021), arXiv, International Geothermal Association
(29) Wapenaar, K., and van IJsseldijk, J., 2020, Employing internal multiples in time-lapse seismic monitoring, using the Marchenko method, 82nd annual EAGE meeting, Amsterdam, (4 pages), pdf-file
(30) Wapenaar, K., Staring, M., Brackenhoff, J., Zhang, L., Thorbecke, and Slob, E., 2020, An overview of Marchenko methods, 82nd annual EAGE meeting, Amsterdam, Internal multiple removal - status, challenges and road ahead (2 pages), pdf-file
(31) Brackenhoff, J., van IJsseldijk, J., , and Wapenaar, K., 2020, Data-driven internal multiple elimination applications using imperfectly sampled reflection data, 82nd annual EAGE meeting, Amsterdam, Internal multiple removal - status, challenges and road ahead (2 pages), pdf-file
(32) van IJsseldijk, J., and Wapenaar, K., 2020, Correcting for imperfectly sampled data in the iterative Marchenko scheme, 82nd annual EAGE meeting, Amsterdam, (4 pages), pdf-file
(33) Staring, M., Zhang, L., Thorbecke, J, and Wapenaar, K., 2020, A new role for adaptive filters in Marchenko equation-based methods for the attenuation of internal multiples, 82nd annual EAGE meeting, Amsterdam, Internal multiple removal - status, challenges and road ahead (2 pages), pdf-file
(34) Shoja, S.M.A., Meles, G.A., and Wapenaar, K., 2020, A proposal for Marchenko-based target-oriented full waveform inversion, 82nd annual EAGE meeting, Amsterdam, (4 pages), pdf-file
(38) Staring, M., and Wapenaar, K., 2020, Three-dimensional Marchenko internal multiple attenuation on narrow azimuth streamer data of the Santos Basin, Brazil: Geophysical Prospecting, Vol. 68, 1864-1877. pdf-file.
(39) Al Hasani, M., Drijkoningen, G., and Reinsch, T., 2020, Examining directional strain sensitivity of shaped optical fibre embedded in polyurethane strip: arXiv
(40) Wapenaar, K., 2020, A modified Marchenko method to retrieve the wave field inside layered metamaterial from reflection measurements at the surface: J. Acoust. Soc. Am., Vol. 148 (2), 939-953. pdf-file Copyright (2020) Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America. The article appeared in JASA and may be found at doi.org/10.1121/10.0001761.
(41) Wapenaar, K., 2020, The Marchenko method for evanescent waves: Geoph. J. Int., Vol. 223, 1412-1417. pdf-file.
(42) Reinicke, C., Dukalski, M., and Wapenaar, K., 2020, Comparison of monotonicity challenges encountered by the inverse scattering series and the Marchenko demultiple method for elastic waves: Geophysics, Vol. 85 (5), Q11-Q26. pdf-file
(43) Minato, S., Wapenaar, K., and Ghose, R., 2020, Elastic least-squares migration for quantitative reflection imaging of fracture compliances: Geophysics, Vol. 85 (6), S327-S342. pdf-file
(44) van IJsseldijk, J., and Wapenaar, K., 2021, Adaptation of the iterative Marchenko scheme for imperfectly sampled data: Geoph. J. Int., Vol. 224, 326-336. pdf-file.
(45) Brackenhoff, J., Thorbecke, J., and Wapenaar, K., 2022, 3D virtual seismology: IEEE Transactions on Geoscience and Remote Sensing, DOI: 10.1109/TGRS.2021.3076292. pdf-file.
(46) Kiraz, M.S.R., Snieder, R., and Wapenaar, K., 2020, Marchenko focusing without up/down decomposition, 90th annual SEG meeting, Houston, 3593-3597, pdf-file
(47) Alfaraj, H., Brackenhoff, J., and Wapenaar, K., 2020, Obtaining angle-dependent reflectivity using the Marchenko redatuming method, 82nd annual EAGE meeting, Amsterdam, Internal multiple removal - status, challenges and road ahead (2 pages), pdf-file
(48) Meles, G.A., Zhang, L., Thorbecke, J, Wapenaar, K., and Slob, E., 2020, Marchenko multiple elimination: from point-source to plane-wave datasets applications, 82nd annual EAGE meeting, Amsterdam, Internal multiple removal - status, challenges and road ahead (2 pages), pdf-file
(49) Thorbecke, J., Zhang, L., Wapenaar, K., and Slob, E., 2021, Implementation of the Marchenko multiple elimination algorithm: Geophysics, Vol. 86 (2), F9-F23. pdf-file. Bright spots column pdf-file.
(50) Wapenaar, K., Snieder, R., de Ridder, S., and Slob, E., 2021, Green's function representations for Marchenko imaging without up/down decomposition: Geoph. J. Int., Vol. 227, 184-203. pdf-file
(51) Staring, M., Dukalski, M., Belonosov, M., Baardman, R.H., Yoo, J., Hegge, R.F., van Borselen, R., and Wapenaar, K., 2021, Robust estimation of primaries by sparse inversion and Marchenko equation-based workflow for multiple suppression in the case of a shallow water layer and a complex overburden: A 2D case study in the Arabian Gulf: Geophysics, Vol. 86 (2), Q15-Q25. pdf-file
(52) Brackenhoff, J., 2021, Monitoring and forecasting of seismic wavefields in the subsurface: PhD thesis pdf-file
(53) Kiraz, M.S.R., Snieder, R., and Wapenaar, K., 2021, Focusing waves in an unknown medium without wavefield decomposition: JASA Express Lett., Vol. 1 (5), 055602. pdf-file Copyright (2021) Authors. This article is distributed under a Creative Commons Attribution (CC BY) License. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America. The article appeared in JASA Express Letters and may be found at doi/10.1121/10.0004962.
(54) Reinicke, C., Dukalski, M., and Wapenaar, K., 2021, Internal multiple elimination: Can we trust an acoustic approximation?: Geophysics, Vol. 86 (5), WC41-WC54. pdf-file
(55) Wapenaar, K., Brackenhoff, J., Dukalski, M., Meles, G., Reinicke, C., Slob. E., Staring, M., Jan Thorbecke, J., van der Neut, J., and Zhang, L., 2021, Marchenko redatuming, imaging and multiple elimination, and their mutual relations: Geophysics, Vol. 86 (5), WC117-WC140. pdf-file
(56) Wapenaar, K., and de Ridder, S., 2022, On the relation between the propagator matrix and the Marchenko focusing function: Geophysics, Vol. 87 (2), A7-A11. pdf-file
(57) Pijnenburg, R., Laumann, S., Wessels, R., ter Maat, G., Armstrong, L., Bienkowski, J., Sleeman, R., Vardon, P., Bruhn, D., Barnhoorn, A., Niemeijer, A., Plumper, O., Willingshofer, E., Spiers., Wapenaar, K., Trampert, J., and Drury, M., 2021, EPOS-NL is the Dutch solid Earth science infrastructure for research on georesources and geohazards, First EAGE Workshop on Induced Seismicity, pdf-file
(58) Almobarak, M., van IJsseldijk, J., and Wapenaar, K., 2021, Plane-wave Marchenko imaging method: Field data application, 82nd annual EAGE meeting, Amsterdam, (4 pages), pdf-file
(59) Van der Neut, J., Brackenhoff, J., Meles, G., Zhang, L., Slob, E., and Wapenaar, K., 2021, On the benefits of auxiliary transmission data for Marchenko-based Green's function retrieval, 82nd annual EAGE meeting, Amsterdam, (4 pages), pdf-file
(60) van IJsseldijk, J., and Wapenaar, K., 2021, Discerning small time-lapse traveltime changes by isolating the seismic response of a reservoir using the Marchenko method, First International Meeting for Applied Geoscience and Energy, Denver, 3449-3453, pdf-file
(61) Kiraz, M.S.R., Snieder, R., and Wapenaar, K., 2021, Marchenko without up/down decomposition on the Marmousi model and retrieval of the refracted waves: Are they caused by the Marchenko algorithm?, First International Meeting for Applied Geoscience and Energy, Denver, 3280-3284, pdf-file
(62) Wapenaar, K., Snieder, R., de Ridder, S., and Slob, E., 2021, Do we need up/down decomposition for Marchenko imaging?, First International Meeting for Applied Geoscience and Energy, Denver, 3275-3279, pdf-file
(63) Wapenaar, K., 2022, Wave-field representations with Green's functions, propagator matrices, and Marchenko-type focusing functions: J. Acoust. Soc. Am., Vol. 151 (1), 587-608. pdf-file
(64) Van der Neut, J., Brackenhoff, J., Meles, G., Zhang, L., Slob, E., and Wapenaar, K., 2022, On the retrieval of forward-scattered waveforms from acoustic reflection and transmission data with the Marchenko equation: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 69 (5), 1775-1786. pdf-file
(65) Van der Neut, J., Brackenhoff, J., Meles, G.A., Slob, E., and Wapenaar, K., 2022, Marchenko Green's function retrieval in layered elastic media from two-sided reflection and transmission data: Applied Sciences, Vol. 12 (15), 7824. pdf-file
(66) Wapenaar, K., and Slob, E., 2022, Reciprocity and representations for wave fields in 3D inhomogeneous parity-time symmetric materials: Symmetry, Vol. 14 (11), 2236. pdf-file
(67) Diekmann, L., Vasconcelos, I., Wapenaar, K., Slob, E., and Snieder, R., 2023, Wavefield focusing using a generalised, potentially asymmetric homogeneous Green's function: Wave Motion, Vol. 116, 103071. pdf-file
(68) Shoja, A., van der Neut, J., and Wapenaar, K., 2023, Target-oriented least-squares reverse-time migration using Marchenko double-focusing: reducing the artefacts caused by overburden multiples: Geoph. J. Int., Vol. 233, 13-32. pdf-file
(69) Shoja, S.M.A., van der Neut, J., and Wapenaar, K., 2022, Reducing the overburden-related artifacts in target-oriented least-squares migration by Marchenko double-focusing, 83rd annual EAGE meeting, Madrid, (4 pages), pdf-file
(70) Van der Neut, J., Brackenhoff, J., Meles, G., Slob, E., and Wapenaar, K., 2022, Elastodynamic Marchenko Green's function retrieval from two-sided reflection and transmission data, 83rd annual EAGE meeting, Madrid, (4 pages), pdf-file
(71) Meles, G., Reinicke, C., Dukalski, M., and Wapenaar, K., 2022, Acoustic plane-wave Marchenko multiple elimination applied on complex marine data, 83rd annual EAGE meeting, Madrid, (4 pages), pdf-file
(72) Dukalski, M., Reinicke, C., and Wapenaar, K., 2022, Implications of evanescent waves for the Marchenko method through the lens of the transfer-scattering matrix relation, 83rd annual EAGE meeting, Madrid, (4 pages), pdf-file
(73) Dukalski, M., Reinicke, C., and Wapenaar, K., 2022, Towards understanding the impact of the evanescent elastodynamic mode coupling in Marchenko equation based de-multiple methods, Second International Meeting for Applied Geoscience and Energy, Houston, 2827-2831, pdf-file
(74) Wapenaar, K., de Ridder, S., Dukalski, M., and Reinicke, C., 2022, The propagator and transfer matrix for a 3D inhomogeneous dissipative acoustic medium, expressed in Marchenko focusing functions, Second International Meeting for Applied Geoscience and Energy, Houston, 3141-3145, pdf-file
(75) Van IJsseldijk, J., van der Neut, J., Thorbecke, J., and Wapenaar, K., 2023, Extracting small time-lapse traveltime changes in a reservoir using primaries and internal multiples after Marchenko-based target zone isolation: Geophysics, Vol. 88 (2), R135-R143. pdf-file
(76) Brackenhoff, J., Thorbecke, J., Meles, G., Koehne, V., Barrera, D., and Wapenaar, K., 2022, 3D Marchenko applications: implementation and examples: Geophysical Prospecting, Vol. 70, 35-56. pdf-file
(77) Wapenaar, K., Dukalski, M., Reinicke, C., and Snieder, R., 2023, Propagator and transfer matrices, Marchenko focusing functions and their mutual relations: Geoph. J. Int., Vol. 235, 1403-1419. pdf-file
(78) Shoja, A., van der Neut, J., and Wapenaar, K., 2023, Target-enclosed least-squares seismic imaging: IEEE Transactions on Geoscience and Remote Sensing, Vol. 61, 4503612. pdf-file
(79) Wapenaar, K., Brackenhoff, J., de Ridder, S., Slob, E., and Snieder, R., 2023, On Green's functions, propagator matrices, focusing functions and their mutual relations, 84th annual EAGE meeting, Vienna, (4 pages), pdf-file
(80) Reinicke, C., Dukalski, M., and Wapenaar, K., 2023, Minimum-phase property and reconstruction of elastodynamic dereverberation matrix operators: Geoph. J. Int., Vol. 235, 1-11. pdf-file
(81) Van IJsseldijk, J., Brackenhoff, J., Thorbecke, J., and Wapenaar, K., 2023, Time-lapse applications of the Marchenko method on the Troll field: Geophysical Prospecting, Vol. 72, 1026-1036. pdf-file
(82) Brackenhoff, J., and Wapenaar, K., 2023, On evanescent wave field retrieval with the Marchenko method in 2D settings: Available at arXiv
(83) Al Hasani, M., and Drijkoningen, G., 2023, Experiences with distributed acoustic sensing using both straight and helically wound fibers in surface-deployed cables -- A case history in Groningen, The Netherlands: Geophysics, Vol. 88 (6), B369-B380. pdf-file
(84) Van IJsseldijk, J., Hajibeygi, H., and Wapenaar, K., 2023, A framework for subsurface monitoring by integrating reservoir simulation with time-lapse seismic surveys: Scientific Reports, Vol. 13, 13661. pdf-file The paper can be accessed at the Scientific Reports website via this html-link.
(85) Kiraz, M.S.R., Snieder, R., and Wapenaar, K., 2023, The role of the background velocity model for the Marchenko focusing of reflected and refracted waves: Available at arXiv
(86) Shirmohammadi, F., Draganov, D., van IJsseldijk, J., Ghose, R., Thorbecke, J., and Wapenaar, K., 2023, Application of the Marchenko method to a land seismic dataset: Geophysical Prospecting (under review). Available at arXiv
(87) Dalkhani, A.R., Al Hasani, M., Drijkoningen, G., and Weemstra, C., 2023, Transdimensional surface wave tomography of the near-surface: Application to DAS data: Geophysics (under review). Available at arXiv
(88) Zhang, D., and Drijkoningen, G., 2023, Shallow shear-wave (SV) reflection surveying with distributed acoustic sensing in Zuidbroek, the Netherlands: EAGE Near Surface Geoscience '23, Edinburgh (4 pages). Available at arXiv
(89) Van IJsseldijk, J., Al Hasani, M., Verschuur, E., Drijkoningen, G., and Wapenaar, K., 2023, Application of virtual seismology to DAS data in Groningen: Available at arXiv
(90) Shoja, A., van der Neut, J., and Wapenaar, K., 2024, Target-oriented least-squares reverse-time migration with Marchenko redatuming and double-focusing: Field data application: Geophysics, Vol. 89 (3), S267-S274. pdf-file.
(91) Thorbecke, J., Almobarak, M., van IJsseldijk, J., Brackenhoff, J., Meles, G., and Wapenaar, K., 2024, Design, implementation and application of the Marchenko plane-wave algorithm: Computers & Geosciences, Vol. 187, 105577. pdf-file.
(92) Van IJsseldijk, J., 2023, Time-lapse monitoring with virtual seismology: Applications of the Marchenko method for observing time-lapse changes in subsurface reservoirs: PhD thesis pdf-file
(93) Shoja, A., 2023, Target-oriented seismic imaging and inversion with Marchenko redatuming and double-focusing: PhD thesis pdf-file
(94) Al Hasani, M., 2024, Distributed Acoustic Sensing using straight, sinusoidally and helically shaped fibres for seismic applications: PhD thesis pdf-file
(95) Dalkhani, A., 2024, Transdimensional surface wave inversion: 1D, 2D and 3D applications: PhD thesis pdf-file
(96) Shirmohammadi, F., 2024, Methodology for layer-specific imaging and monitoring (tentative title): PhD thesis pdf-file (to appear end-2024)