Quijotic Research
(Id − 𝔼) = δ Π D
Stochastic calculus as operator factorization.
From adjoint identities to information limits.
Founded by Ramiro Fontes · New York

Research Papers
The Operator Derivative Program
A unified framework in which the operator derivative D = δ* — defined by duality with the stochastic integral — yields representation theorems, Leibniz defects, and information-theoretic structure across stochastic calculus, mathematical finance, and AI memory architecture.
PAPER I
The Operator Derivative in Continuous Stochastic Calculus: A Hilbert Energy Space Framework
Defines D = δ* via adjoint identity. Clark-Ocone, variance identity, and chain rule follow from duality alone. The representer rigidity theorem — deterministic representers force deterministic volatility — is the genuinely non-Malliavin headline result.
PAPER II
Operator Factorization Beyond Hilbert Spaces: Representability Obstructions and Leibniz Defects for Stable Lévy Processes
Extends the framework to Banach spaces and Lévy processes. The Leibniz defect Γ(F,G) appears as a structural invariant measuring the non-Gaussian content — the part of the interaction that has no stochastic integral representation.
PAPER III
The Boundary of Hedgeability: Pricing and Hedging in Volterra-Lévy Markets
First application: mathematical finance. The kernel-weighted Leibniz defect equals the structurally unhedgeable risk in markets with memory and jumps. The VRNC (Volterra Risk-Neutral Constraint) governs pricing. Formally verified in Lean 4 (zero sorry, zero axioms).
PAPER IV
Fractional Memory for Attention-Based Systems: Theory, Information Limits, and Implementation
Second application: AI memory. The fractional memory process provides persistent state with power-law retention, O(N) query cost, and provable information limits. The Leibniz defect becomes the memory gap — the irreducible information loss from discontinuous updates.

Formal Verification
Lean 4 Formalizations
The algebraic spine of the program is formally verified in the Lean 4 proof assistant. Zero sorry. Each formalization carries exactly one stochastic analysis input as a structure field; all downstream results are proved as theorems.
-- The operator factorization identity
theorem factorization_identity
  (F : HilbertEnergySpace.Element) :
  (Id - expect) F = divergence (proj (D F)) :=
  adjoint_identity F ▸ rfl

-- Zero sorry.

About
Ramiro Fontes
Mathematician and quantitative researcher. PhD in mathematics (Kent State University). Director of quantitative risk at a major financial institution. The research program originated from a 2010 dissertation on stochastic differentiation theory and returned to active development in 2025.

Research

Stochastic calculus, operator theory, fractional dynamics, mathematical finance, AI memory architecture. Four papers, three Lean formalizations, one provisional patent.

Quijotic Research

Independent research entity. The name comes from the impossible-seeming quality of the problems — and the stubbornness required to pursue them.

Contact

ramirofontes@gmail.com
New York, NY