Leiden University PhD Position in Complex Networks: Modelling, Computation and Data Analysis

Leiden University PhD Position in Complex Networks: Modelling, Computation and Data Analysis

How can a network model retain real spatial structure, clustering and heterogeneity while remaining mathematically understandable? This PhD joins probability, computation and data analysis at Leiden’s Mathematical Institute (MI) and LIACS, starting as soon as possible and no later than April 2027. Apply by 24 November 2026; interviews are expected from 1 December. Moritz Otto and Akrati Saxena co-supervise, with Michel Mandjes as promotor. It is a 38-hour salaried position, initially one year and extended for three after positive evaluation. This is a promising bridge between probability theory and computational network science, with research balance shaped around the candidate. Official Leiden complex networks PhD

Research work and unresolved problem

The aim is to explain observed structural features using mathematically tractable network models, combining theory, computation and real-world data. Explicit features include spatial structure, clustering, heterogeneity and connectivity; possible directions include network science, spatial networks, random graphs and data-driven analysis. The doctorate produces a publication-based thesis and involves limited teaching/supervision. The advert does not select a final network dataset, model family or algorithm. Official Leiden complex networks PhD

The hard problem is retaining real structural features without losing analytic understanding. A random model can fit degree patterns yet miss communities or spatial dependence; an accurate algorithm can perform differently for small, dense or weakly connected groups. Useful preparation would connect a generative assumption to a measurable statistic, prove or explain its behaviour, and evaluate it against synthetic and held-out real networks. This is an applicant proposal, not an assigned protocol. Geometric community recovery 2026 author text Dynamic random connection subgraphs 2025 author text Saxena group fairness community detection 2025

Ask whether spatial geometry is observed, which source of heterogeneity matters, and how the thesis will balance asymptotic proofs with finite-data validation. Fairness is a relevant neighbouring expertise through AlFa, but the advert does not require every thesis chapter to develop a fairness algorithm. Official Leiden complex networks PhD AlFa research initiative

School, subject and doctoral training

Leiden University awards the doctorate and employs the candidate at MI, with LIACS affiliation; the candidate joins AlFa at LIACS and the Probability group at MI and collaborates closely with Network Science. MI covers probability, statistics/data science and other mathematics; the computer-science link supports algorithms and real network data. QS 2027 places Leiden joint 119th overall, a broad institutional signal rather than a network-science ranking. Group membership, seminars and recent papers are more specific evidence of fit; no personal compute allocation or dataset access is promised. Official Leiden complex networks PhD Leiden Probability Theory Group LIACS Network Science people Mathematical Institute environment AlFa research initiative QS 2027 Leiden institution

The Graduate School of Science requires a Training and Supervision Plan within two months, covering research, supervision, training and possible teaching. Its earlier deadline controls over the general three-month statement. Employee candidates complete 140 hours academic activities and 140 hours transferable skills, including mandatory Inform and Scientific Conduct, with institute-specific additions and LUCRIS records. These are training hours, not a cap on all teaching work. Science Training and Supervision Plan Science PhD training programme

University regulations provide academic independence, supervisory responsibilities, annual training-plan review and the dissertation/committee/public-defence process. The job's first-year extension evaluation is a separate employment gate. Registration follows institute introduction and requires certified master's records/English translation and formal appointment of the supervisory team. Confirm MI/LIACS thesis requirements and teaching allocation. Official Leiden complex networks PhD Leiden doctoral regulations 2024 Graduate Science admission registration

Supervisors and recent research evidence

Otto is Assistant Professor of Probability, with KIT mathematics training and earlier Aarhus research. His interests directly connect spatial random graphs, inference and limit theory. Saxena is listed as Assistant Professor in the current LIACS Network Science group and founded AlFa, addressing algorithmic bias and fairness. Mandjes is Professor of Probability and Operations Research at MI since October 2023, with previous industry/CWI/university experience. The official advert assigns his promotor role; it does not establish that he provides all daily mentoring. Ask how the three share meetings, decisions and availability. Moritz Otto current academic page Leiden Probability Theory Group LIACS Network Science people Michel Mandjes official profile AlFa research initiative

Hoeneveld, Otto and Sala (2026): geometric community recovery

Hoeneveld, Otto and Sala, 2026 author version: a polynomial-time, discretisation-free procedure recovers communities in a geometric hidden-community model, using initialisation, propagation and likelihood refinement. Continuous geometry/identifiability conditions matter; experiments beyond the guaranteed regime are not additional universal proofs. Full model, main result, proof sketch and discussion were reviewed. Geometric community recovery 2026 author text

Hazra, Kriukov, Mandjes and Otto (2025): dynamic fluctuations

Hazra, Kriukov, Mandjes and Otto, 2025 author version: a functional central limit theorem for dynamic random-connection subgraph counts uses a dynamic cumulant method to establish tightness. The setup includes stationary Markov activity and toroidal spatial boundaries. It supplies fluctuation tools, not a finite-network forecasting guarantee. Full text was read; individual contribution roles were not found. Dynamic random connection subgraphs 2025 author text

De Vink, Takes and Saxena (2025): community-level fairness

De Vink, Takes and Saxena, 2025 PLOS ONE: community-wise matching and a slope-based fairness score compare 24 methods across structural properties and synthetic/real networks. No single class dominates. Limitations include undirected/unweighted non-overlapping communities, ground truth and roughly linear disparity trends. Saxena's stated roles include conceptualisation, methodology, supervision, validation and writing; De Vink led investigation. The full publisher text/contributions were reviewed. Saxena group fairness community detection 2025

These papers illustrate the theory/data bridge. They are evidence of surrounding expertise, not already-assigned thesis chapters or evidence that every real network meets the models' assumptions.

Salary, contract and living costs

The official range is €3,204–€4,051 gross per month on scale P, 38 hours, plus 8% holiday allowance, 8.3% year-end bonus and ABP pension. There is public-transport commuting reimbursement, at least 29 leave days at 38 hours, and equipment/home-working arrangements. Hybrid work is possible within the Netherlands if the work permits it; this is not permission to remain abroad. First-year research progress, capabilities and compatibility determine extension. Personal tax/pension deductions, future pay schedules and any tax concession need HR confirmation. Official Leiden complex networks PhD Leiden employment conditions

This is employment rather than an overseas master's-fee studentship. No personal doctoral fee liability is specified in the vacancy; confirm registration, training, conference and dissertation costs rather than importing unrelated international master's tariffs. Extra completion time beyond the appointment is not promised. Official Leiden complex networks PhD Graduate Science admission registration

Leiden's 2026/27 student brochure estimates €1,020–€2,020 per month (€12,240–€24,240 per year) including rent/utilities of €500–1,000. It is a broad student planning proxy, not a private researcher apartment or employee-insurance quote. Rent should not be added twice. SCIS works with providers offering researcher/PhD accommodation and short-stay staff studios, but availability, deposits, lease duration and insurance are individual. Obtain an actual housing quote and net-pay illustration before estimating savings. Leiden 2026/27 living-cost brochure SCIS staff housing partnerships

Applicant fit and preparation

The advert seeks mathematics, computer science or a closely related degree, relevant graph/probability/random-graph/complex-system/topological-data-analysis knowledge, programming preferably Python, academic motivation, English and independent/team working. Those finishing their master's by early spring 2027 may apply. Formal admission requires a Dutch master's or equivalent; “university degree” in the short requirement should not be read as a guaranteed bachelor's-only route. Relocation and official Netherlands residence are required at the start. Official Leiden complex networks PhD Graduate Science admission registration Leiden general doctoral admissions

Submit CV, full BSc/MSc transcripts, a cover letter no more than two pages, a recent paper/thesis writing sample, and at least one consenting academic referee's contact details; no reference letters are required. Use the university application tool. The post gives no IELTS/TOEFL threshold; ask the Graduate School about any evidence needed instead of borrowing a master's-course rule. Official Leiden complex networks PhD Leiden general doctoral admissions

A useful writing sample can link a graph-generating assumption, an inference method and a testable conclusion. Explain whether the data provide any positions or labels the model assumes, and distinguish asymptotic results from finite-network performance. Identify your own contribution, failure cases and reproducibility conditions. These are preparation suggestions, not extra application requirements or assigned thesis work.

Career and transferable skills

Theory, statistical modelling, graph algorithms and reproducible analysis can transfer to academic probability/network research, data science and research-intensive industry/public organisations. Group alumni include a Statistics Netherlands researcher, one example rather than a placement rate. Science career advisers and its platform support early planning, without guaranteeing a position. LIACS Network Science people Science career services after PhD

Next actions and questions

Contact m.f.p.otto@math.leidenuniv.nl or a.saxena@liacs.leidenuniv.nl with a short explanation of your preferred theory/data balance; procedural questions go to hr@math.leidenuniv.nl. At interview, discuss a model assumption and its observable consequences, proposed data and proof goals, the three-person supervision structure and evaluation criteria. Before accepting, confirm the first-year decision, remaining three-year funding, teaching, resources, housing and completion costs. The role is unusually open to candidate strengths, so establish a feasible mathematical scope rather than promising every network method.

References

Recruitment, institutional profiles and paper assessments retain their October 2026 evidence dates. The advertised deadline does not establish that the vacancy remains available. The first two studies are author versions, with their stated theoretical/reading boundaries; the third is the publisher study. The study-specific reading limits are set out above.

Project, supervision and research environment

• Official Leiden complex networks PhD
• Moritz Otto current academic page
• Leiden Probability Theory Group
• LIACS Network Science people
• Michel Mandjes official profile
• Mathematical Institute environment
• AlFa research initiative

Papers and training

• Geometric community recovery 2026 author text
• Dynamic random connection subgraphs 2025 author text
• Saxena group fairness community detection 2025
• Science Training and Supervision Plan
• Science PhD training programme
• Leiden doctoral regulations 2024
• Graduate Science admission registration

Finance, applications and careers

• Leiden employment conditions
• Leiden 2026/27 living-cost brochure
• SCIS staff housing partnerships
• Science career services after PhD
• QS 2027 Leiden institution
• Leiden general doctoral admissions