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Agent-Like Observers in Extended Wigner's Friend Scenarios on Quantum Computers
Item type: Master Thesis
Laux, Joshua (2026)
The Wigner’s friend thought experiment raises the question of whether quantum the-
ory can be applied consistently to systems that include observers. Extended Wigner’s
Friend Scenarios develop this question by considering several observers who may as-
sign different descriptions to the same experiment. In the Local Friendliness (LF)
framework, these scenarios lead to experimentally testable inequalities derived from
assumptions such as Absoluteness of Observed Events and Local Agency. Motivated by
the “Thoughtful” version of the Local Friendliness no-go theorem, which points to-
wards future LF tests with human-level artificial agents implemented on quantum com-
puters, this thesis implements the “friend” with explicit agent-like functionality within
a reversible quantum circuit. Several such agents are constructed and embedded into a
one-friend Extended Wigner’s Friend Scenario, following recent work that uses quantum
computers as a platform for LF violations with more sophisticated “friend” systems.
These agents store measurement outcomes, condition later operations on stored infor-
mation, and, in the most structured case, use Born-rule probabilities to bet on the
outcomes of their own future observations. The circuits are implemented in Qiskit,
simulated ideally and with IBM-device noise models, and executed on ibm_marrakesh.
In ideal simulations, all agent implementations reproduce the maximal quantum vio-
lation of a Local Friendliness inequality up to finite-shot fluctuations. Hardware runs
show positive Local Friendliness violations for all implemented agents, with decreasing
violation strength consistent with greater noise accumulation. The observed violations
also remain above an estimated bound obtained by considering relaxations of a Local
Friendliness assumption. These results provide a first step towards more structured
agent-like friend models in LF experiments on quantum computers.
What drives students’ decision to enroll abroad for tertiary education?
Item type: Journal Article
Zubovic A. (2026)
A key question in understanding student mobility is how students weigh immediate considerations against the potential long-term benefits of studying abroad. Using subjective expectation data from students in Bosnia and Herzegovina, I find that students prioritize immediate factors–social life, parental support, and education quality–over later outcomes like career and financial stability. Removing admission and financial barriers raises study-abroad intentions and shifts attention toward career satisfaction and education quality. Networks also matter: larger networks narrow focus to immediate concerns, while smaller ones broaden consideration. The findings highlight how student emigration differs from adult migration, emphasizing short-term motives and networks.
Metabolic strategies of Enterobacteriaceae gut colonization
Item type: Review Article
Schubert C.; Hardt W.D. (2026)
Enterobacteriaceae are facultative anaerobic bacteria that commonly colonize the gut and include both commensals and diverse pathogens. They can flexibly adapt their metabolic strategy to grow in the intestinal environment. As Enterobacteriaceae blooms are linked to enteric disease and the dissemination of antibiotic resistance, a deeper understanding of the factors that drive their expansion is needed. In the healthy intestine, Enterobacteriaceae subsist on low concentrations of diet-derived and mucus-derived monosaccharides that feed glycolysis and mixed-acid fermentation. Inflammation reshapes this niche as immune-derived oxidants generate new terminal electron acceptors, such as nitrate or tetrathionate, and facilitate oxygen diffusion into the gut lumen, thereby expanding facultative anaerobes and broadening the range of usable substrates. In this Review, we discuss recent evidence across Escherichia coli, Citrobacter rodentium, Klebsiella spp. and Salmonella Typhimurium to define a conserved, monosaccharide-fuelled programme for colonization and its inflammatory remodelling. Competition with commensal bacteria for these nutrients underpins colonization resistance, and genetic differences can determine competitive fitness. Metabolism lies at the core of these ecological dynamics, and recognizing its central role will help guide the design of future therapies.
Search for heavy resonances decaying into two Higgs bosons in the bb¯τ+τ- final state in proton–proton collisions at s=13TeV
Item type: Journal Article
Sosnov D.; Oreshkin V.; Murzin V.; et al. (2026)
A search is presented for massive narrow-width resonances in the mass range of 1–4.5TeV, decaying into pairs of Higgs bosons (HH). The search uses proton–proton collision data at a center-of-mass energy of 13TeV collected with the CMS detector at the CERN LHC during 2016–2018, corresponding to an integrated luminosity of 138fb-1. The analysis targets final states where one Higgs boson decays into a pair of bottom quarks and the other into a pair of tau leptons, X→HH→bb¯τ+τ-. It uses a single large radius jet to reconstruct the H→bb¯ decay, while the H→τ+τ- decay products can either be contained within a single large radius jet or appear as two isolated tau leptons. The observed data are consistent with standard model background expectations. Upper limits at 95% confidence level are set on the production cross section for resonant HHproduction for masses between 1 and 4.5TeV. This analysis sets the most sensitive limits to date on X→HH→bb¯τ+τ- decays in the mass range of 1.4–4.5TeV.
A tumor profiling resource for ovarian cancer: insights into chemotherapy-driven heterogeneity and personalized treatment strategy
Item type: Journal Article
Jacob F.; Wegmann R.; Ficek-Pascual J.; et al. (2026)
In women with high-grade serous ovarian cancer, chemotherapy remains the primary standard treatment, despite growing recognition of the disease as highly heterogeneous. Here, we examine the feasibility and clinical utility of comprehensive multimodal molecular profiling to inform treatment decisions. We analyze blood, single-cell and bulk tumor tissue, and malignant ascites using up to eleven technologies (DNA, RNA, protein, and functional assays) within a four-week turnaround time. Hypothetical treatment recommendations are altered for 76% of patients, and multi-omics-guided maintenance therapy is associated with prolonged overall survival in a subset of patients. Subsequent cohort analysis reveals distinct cellular and molecular profiles in ascites-derived single-cells compared to solid tumor tissue, unique per-patient ex vivo drug responses, and a marked increase in cancer cell heterogeneity following chemotherapy exposure. This coincides with genomic signature alterations in whole-genome-amplified patients. Our data suggest that molecularly guided treatments should be tested as adjuvant therapies prior to chemotherapy in the future.