The Endogenous Field Formation Hypothesis: Constitutive Transitions, Causal Genesis, and Governance in Interacting Language and Signal Systems

Contemporary artificial-intelligence systems can change their behavior through conversational history, persistent memory, tool use, policy routing, multi-agent interaction, and adaptive mechanisms without changing the underlying language-model weights. Such changes invite a stronger question than whether context matters: under what conditions, if any, does the activity occurring inside an interacting system give rise to a new mission-relative relational constitution that deserves qualification as a Field? This article formulates the Endogenous Field Formation (EFF) Hypothesis as a bounded and refutable research programme, not as an empirical result or a claim that language models spontaneously acquire privileged ontological structures. It separates ordinary state updates, authorized relational reconfiguration, constitutive transition candidates, and scientifically qualified formation. A candidate EFF event requires an independently specified observation boundary, a predeclared field-identity and qualification contract, participant-originated causal changes, a demonstrable modification of admissible relations or operative constraints, discriminating interventions, and survival against strong non-Field alternatives. The analysis distinguishes system-level Large Language Fields from heterogeneous Large Signal Fields, and treats adaptive graphs, agent protocols, memory systems, causal models, and conventional policy engines as indispensable comparators. A formal transition framework, observational-equivalence arguments, intervention protocols, negative-control families, and multi-stage validation architecture are developed. The previous Field Control Gap pilot supplies only a narrow methodological precedent: sixteen deterministic cases were classified equally well by a field-contract implementation and an information-matched conventional workflow; it was not an EFF experiment. The paper proposes independent trials in instrumented systems and explicitly withholds claims of Field emergence, universal emergence laws, internal host-model observability, or superiority until prospective evidence establishes them.