{"id":{"repo_id":"heid-thes","oai_identifier":"oai:archiv.ub.uni-heidelberg.de:30157"},"canonical_url":"https://search.dev.ndltd.org/etd/heid-thes/oai:archiv.ub.uni-heidelberg.de:30157","repository":{"repo_id":"heid-thes","name":"Universität Heidelberg ; Thes","base_url":"http://archiv.ub.uni-heidelberg.de/volltextserver/cgi/oai2"},"display":{"title":"A Network Approach to Atomic Spectra","abstract":"In this thesis we investigate atomic spectra using network theory. The spectroscopic data of an atom is mapped onto a network by identifying nodes with energy levels and links with optical transitions. These so-called spectroscopic networks are almost bipartite, which is ascribed to the parity symmetry. We apply community detection to these networks and show that the communities found correspond to known quantum numbers. For thorium II we demonstrate that the states of additional communities detected form one or two clusters in the energy domain. These clusters correlate with the dominant configurations of the states. We test the ability to use the network to predict quantum mechanical properties of individual states and show that for thorium II parity and J can be predicted with 100% and 95% accuracy respectively. We show that new transitions can be predicted using state of the art methods of link prediction. We benchmark this by a random dropout and demonstrate that depending on the atom 20% to 40% of the transitions can be recovered with few errors using the structural perturbation method. We develop a method that can predict the transitions to new states, for which structural information is given.","abstract_html":"In this thesis we investigate atomic spectra using network theory. The spectroscopic data of an atom is mapped onto a network by identifying nodes with energy levels and links with optical transitions. These so-called spectroscopic networks are almost bipartite, which is ascribed to the parity symmetry. We apply community detection to these networks and show that the communities found correspond to known quantum numbers. For thorium II we demonstrate that the states of additional communities detected form one or two clusters in the energy domain. These clusters correlate with the dominant configurations of the states. We test the ability to use the network to predict quantum mechanical properties of individual states and show that for thorium II parity and J can be predicted with 100% and 95% accuracy respectively. We show that new transitions can be predicted using state of the art methods of link prediction. We benchmark this by a random dropout and demonstrate that depending on the atom 20% to 40% of the transitions can be recovered with few errors using the structural perturbation method. We develop a method that can predict the transitions to new states, for which structural information is given.","abstract_has_math":false,"creators":["Wellnitz, David"],"institution":"Universität Heidelberg","degree_name":null,"degree_level":"master","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Weidemüller, Matthias"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-08-01","date_published":"2018-08-01","updated_at":"2026-07-24T02:31:02Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://www.ub.uni-heidelberg.de/archiv/30157","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Weidemüller, Matthias"]},{"key":"dc:creator","label":"Author","values":["Wellnitz, David"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Universitätsbibliothek Heidelberg"]},{"key":"dc:type","label":"Dc Type","values":["masterThesis"]},{"key":"thesis:degree_level","label":"Degree Level","values":["master"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Universität Heidelberg"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In this thesis we investigate atomic spectra using network theory. The spectroscopic data of an atom is mapped onto a network by identifying nodes with energy levels and links with optical transitions. These so-called spectroscopic networks are almost bipartite, which is ascribed to the parity symmetry. We apply community detection to these networks and show that the communities found correspond to known quantum numbers. For thorium II we demonstrate that the states of additional communities detected form one or two clusters in the energy domain. These clusters correlate with the dominant configurations of the states. We test the ability to use the network to predict quantum mechanical properties of individual states and show that for thorium II parity and J can be predicted with 100% and 95% accuracy respectively. We show that new transitions can be predicted using state of the art methods of link prediction. We benchmark this by a random dropout and demonstrate that depending on the atom 20% to 40% of the transitions can be recovered with few errors using the structural perturbation method. We develop a method that can predict the transitions to new states, for which structural information is given.","In dieser Arbeit untersuchen wir Atomspektren mithilfe von Konzepten der Netzwerktheorie. Wir erzeugen ein sogenanntes spektroskopisches Netzwerk aus Spektraldaten, indem wir Zustände als Knoten und optische Übergänge als Kanten definieren. Wir zeigen, dass spektroskopische Netzwerke aufgrund der Parität in guter Näherung bipartit sind. Mithilfe der Methode der Community Detection finden wir Gruppen von Knoten, welchen identische Quantenzahlen zugeordnet werden können. In Thorium II zeigen sich weitere Hierarchieebenen, die sich als Cluster in den entsprechenden Energien wiederfinden. Innerhalb dieser Cluster haben die Zustände eine ähnliche Elektronenkonfiguration. Aus diesen Resultaten entwickeln wir eine Methode, um Eigenschaften einzelner Zustände vorherzusagen. Für Thorium II bestimmen wir so die richtige Parität in 100% und das richtige J in 95% der Fälle. Die Methode der Link Prediction wird angewandt, um Übergänge vorherzusagen. Wir testen die Structural Perturbation Method und das Nested Stochastic Block Model und werten sie durch zufälliges Entfernen von Kanten aus. Mithilfe der Structural Perturbation Method können je nach Atom 20% bis 40% der Übergänge mit geringer Fehlerquote wiedergefunden werden. Wir entwickeln eine neue Methode, um die Übergänge zu bislang nicht bekannten Zuständen anhand ihrer erwarteten quantenmechanischen Eigenschaften vorherzusagen."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["A Network Approach to Atomic Spectra","Ein netzwerktheoretischer Ansatz zur Untersuchung von Atomspektren"]}]}],"canonical_facts":{"dc:contributor":["Weidemüller, Matthias"],"dc:creator":["Wellnitz, David"],"dc:description.abstract":["In this thesis we investigate atomic spectra using network theory. The spectroscopic data of an atom is mapped onto a network by identifying nodes with energy levels and links with optical transitions. These so-called spectroscopic networks are almost bipartite, which is ascribed to the parity symmetry. We apply community detection to these networks and show that the communities found correspond to known quantum numbers. For thorium II we demonstrate that the states of additional communities detected form one or two clusters in the energy domain. These clusters correlate with the dominant configurations of the states. We test the ability to use the network to predict quantum mechanical properties of individual states and show that for thorium II parity and J can be predicted with 100% and 95% accuracy respectively. We show that new transitions can be predicted using state of the art methods of link prediction. We benchmark this by a random dropout and demonstrate that depending on the atom 20% to 40% of the transitions can be recovered with few errors using the structural perturbation method. We develop a method that can predict the transitions to new states, for which structural information is given.","In dieser Arbeit untersuchen wir Atomspektren mithilfe von Konzepten der Netzwerktheorie. Wir erzeugen ein sogenanntes spektroskopisches Netzwerk aus Spektraldaten, indem wir Zustände als Knoten und optische Übergänge als Kanten definieren. Wir zeigen, dass spektroskopische Netzwerke aufgrund der Parität in guter Näherung bipartit sind. Mithilfe der Methode der Community Detection finden wir Gruppen von Knoten, welchen identische Quantenzahlen zugeordnet werden können. In Thorium II zeigen sich weitere Hierarchieebenen, die sich als Cluster in den entsprechenden Energien wiederfinden. Innerhalb dieser Cluster haben die Zustände eine ähnliche Elektronenkonfiguration. Aus diesen Resultaten entwickeln wir eine Methode, um Eigenschaften einzelner Zustände vorherzusagen. Für Thorium II bestimmen wir so die richtige Parität in 100% und das richtige J in 95% der Fälle. Die Methode der Link Prediction wird angewandt, um Übergänge vorherzusagen. Wir testen die Structural Perturbation Method und das Nested Stochastic Block Model und werten sie durch zufälliges Entfernen von Kanten aus. Mithilfe der Structural Perturbation Method können je nach Atom 20% bis 40% der Übergänge mit geringer Fehlerquote wiedergefunden werden. Wir entwickeln eine neue Methode, um die Übergänge zu bislang nicht bekannten Zuständen anhand ihrer erwarteten quantenmechanischen Eigenschaften vorherzusagen."],"dc:format.medium":["application/pdf"],"dc:publisher":["Universitätsbibliothek Heidelberg"],"dc:title":["A Network Approach to Atomic Spectra","Ein netzwerktheoretischer Ansatz zur Untersuchung von Atomspektren"],"dc:type":["masterThesis"],"thesis:degree_level":["master"],"thesis:institution_name":["Universität Heidelberg"]},"updated_at":"2026-07-24T02:31:02Z"}