Yannis Tzitzikas

On the Computational Complexity of Problems: Formalizing Sensitivity to Uncertainty and Parametric Complexity Classes

Worst-case analysis, the setting of the $P \stackrel{?}{=} NP$ question, measures the cost of a problem as a function of input size alone. Yet problems that are exponential in general often become polynomial, even linear, once a checkable property of the input is known: Partition, for instance, is decidable in linear t...

Exploiting Mapping Corpora and Expert Knowledge for LLM-based Schema Mapping Generation

Sophocles’ Antigone as a Knowledge Graph through a Hybrid Collaborative Workflow with Ontology-Guided LLM Extraction

This work targets a KG for Sophocles’ Antigone that supports two coupled uses: structured retrieval, through integrity and competency questions expressed in SPARQL over dramatic structure and interpretive annotations; and interactive exploration, through a lightweight read client that navigates lines across languages,...