Tootfinder

This https://arxiv.org/abs/2308.13717 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qfi…

Portfolios Generated by Contingent Claim Functions, with Applications to Option Pricing
This paper presents a synthesis of the theories of portfolio generating functions and option pricing. The theory of portfolio generation is extended to measure the value of portfolios generated by positive C^{2,1} functions of asset prices X_1,... , X_n directly, rather than with respect to a numeraire portfolio. If a portfolio generating function satisfies a specific partial differential equation, then the value of the portfolio generated by that function will replicate the value of the functi…

A theory of Lending Protocols in DeFi
Massimo Bartoletti, Enrico Lipparini
https://arxiv.org/abs/2506.15295 https://arxiv.org/pdf/250…

A theory of Lending Protocols in DeFi
Lending protocols are one of the main applications of Decentralized Finance (DeFi), enabling crypto-assets loan markets with a total value estimated in the tens of billions of dollars. Unlike traditional lending systems, these protocols operate without relying on trusted authorities or off-chain enforcement mechanisms. To achieve key economic goals such as stability of the loan market, they devise instead trustless on-chain mechanisms, such as rewarding liquidators who repay the loans of under-…

On a novel probabilistic Sampling Kantorovich operators and their application
Digvijay Singh, Rahul Shukla, Karunesh Kumar Singh
https://arxiv.org/abs/2506.12053

On a novel probabilistic Sampling Kantorovich operators and their application
This article starts with the fundamental theory of stochastic type convergence and the significance of uniform integrability in the context of expectation value. A novel probabilistic sampling kantorovich (PSK-operators) is established with the help of classical sampling operators (SK-operators). We establish the proof of the fundamental theorem of approximation and a lemma corresponding to the PSK- operators. Moreover, some examples are illustrated not only in numerical form but also in a deta…

From Explicit Diffeomorphism Breaking to Spontaneous Unimodularization
Yuri Bonder, Johas D. Morales
https://arxiv.org/abs/2506.12499 https://

From Explicit Diffeomorphism Breaking to Spontaneous Unimodularization
This contribution investigates modifications of General Relativity that allow or mimic energy nonconservation. We focus on Unimodular Gravity (UG), a theory that explicitly breaks diffeomorphism invariance, and show that it can lead to particle acceleration, opening the door to experimental constraints. We also argue that UG admits a well-posed initial value formulation, despite the presence of nondynamical structures. Finally, we introduce a simple model that spontaneously mimics UG, but in wh…

A Unified Theory of Compositionality, Modularity, and Interpretability in Markov Decision Processes
Thomas J. Ringstrom, Paul R. Schrater
https://arxiv.org/abs/2506.09499

A Unified Theory of Compositionality, Modularity, and Interpretability in Markov Decision Processes
We introduce Option Kernel Bellman Equations (OKBEs) for a new reward-free Markov Decision Process. Rather than a value function, OKBEs directly construct and optimize a predictive map called a state-time option kernel (STOK) to maximize the probability of completing a goal while avoiding constraint violations. STOKs are compositional, modular, and interpretable initiation-to-termination transition kernels for policies in the Options Framework of Reinforcement Learning. This means: 1) STOKs can…

Scattering theory on Riemann surfaces I: Schiffer operators, cohomology, and index theorems
Eric Schippers, Wolfgang Staubach
https://arxiv.org/abs/2506.08160

Scattering theory on Riemann surfaces I: Schiffer operators, cohomology, and index theorems
We consider a compact Riemann surface $\mathscr{R}$ with a complex of non-intersecting Jordan curves, whose complement is a pair of Riemann surfaces with boundary, each of which may be possibly disconnected. We investigate conformally invariant integral operators of Schiffer, which act on $L^{2}$ anti-holomorphic one-forms on one of these surfaces with boundary and produce holomorphic one-forms on the disjoint union. These operators arise in potential theory, boundary value problems, approximat…

Enterprise value, economic and policy uncertainties: the case of US air carriers
Bahram Adrangi, Arjun Chatrath, Madhuparna Kolay, Kambiz Raffiee
https://arxiv.org/abs/2506.07766 …

Enterprise value, economic and policy uncertainties: the case of US air carriers
The enterprise value (EV) is a crucial metric in company valuation as it encompasses not only equity but also assets and liabilities, offering a comprehensive measure of total value, especially for companies with diverse capital structures. The relationship between economic uncertainty and firm value is rooted in economic theory, with early studies dating back to Sandmo's work in 1971 and further elaborated upon by John Kenneth Galbraith in 1977. Subsequent significant events have underscored t…

Improving elliptic curve rank classification using multi-value and learned Mestre-Nagao sums
Zvonimir Bujanovi\'c, Matija Kazalicki, Domagoj Vlah
https://arxiv.org/abs/2506.07967

Improving elliptic curve rank classification using multi-value and learned Mestre-Nagao sums
Determining the rank of an elliptic curve E/Q remains a central challenge in number theory. Heuristics such as Mestre--Nagao sums are widely used to estimate ranks, but there is considerable room for improving their predictive power. This paper introduces two novel methods for enhancing rank classification using Mestre--Nagao sums. First, we propose a ``multi-value'' approach that simultaneously uses two distinct sums, S_0 and S_5, evaluated over multiple ranges. This multi-sum perspective sign…

This https://arxiv.org/abs/2504.06481 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

Statistical Physics of the Polarised IKKT Matrix Model
The polarised IKKT matrix model is the worldpoint theory of $N$ D-instantons in a background three-form flux of magnitude $Ω$, and promises to be a highly tractable model of holography. The matrix integral can be viewed as a statistical physics partition function with inverse temperature $Ω^4$. At large $Ω$ the model is dominated by a matrix configuration corresponding to a 'polarised' spherical D1-brane. We show that at a critical value of $Ω^2 N$ the model undergoes a first order phase tr…

This https://arxiv.org/abs/2505.14767 has been replaced.
initial toot: https://mastoxiv.page/@arX…

Ordering the topological order in the fractional quantum Hall effect
We discuss the possible topological order/topological quantum field theory of different quantum Hall systems. Given the value of the Hall conductivity, we constrain the global symmetry of the low-energy theory and its anomaly. Specifically, the one-form global symmetry and its anomaly are presented as the organizing principle of these systems. This information is powerful enough to lead to a unique minimal topological order (or a small number of minimal topological orders). Almost all of the kn…

Scattering theory on Riemann surfaces II: The scattering matrix and generalized period mappings
Eric Schippers, Wolfgang Staubach
https://arxiv.org/abs/2506.08166

Scattering theory on Riemann surfaces II: The scattering matrix and generalized period mappings
We construct a scattering theory for harmonic one-forms on Riemann surfaces, obtained from boundary value problems involving systems of curves and the jump problem. We obtain an explicit expression for the scattering matrix in terms of integral operators which we call Schiffer operators, and show that the matrix is unitary. We also obtain a general association of positive polarizing Lagrangian spaces to bordered Riemann surfaces, which unifies the classical polarizations for compact surfaces of…

This https://arxiv.org/abs/2502.17982 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Kinetic variable-sample methods for stochastic optimization problems
We discuss kinetic-based particle optimization methods and variable-sample strategies for problems where the cost function represents the expected value of a random mapping. Kinetic-based optimization methods rely on a consensus mechanism targeting the global minimizer, and they exploit tools of kinetic theory to establish a rigorous framework for proving convergence to that minimizer. Variable-sample strategies replace the expected value by an approximation at each iteration of the optimizatio…

This https://arxiv.org/abs/2505.24171 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_eco…

A note on the diversity Owen values
Béal et al. (Int J Game Theory 54, 2025) introduce the Diversity Owen value for TU-games with diversity constraints, and provide axiomatic characterizations using the axioms of fairness and balanced contributions. However, there exist logical flaws in the proofs of the uniqueness of these characterizations. In this note we provides the corrected proofs of the characterizations by introducing the null player for diversity games axiom. Also, we establish two alternative characterizations of the …

This https://arxiv.org/abs/2412.17556 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Bekenstein bounds in maximally symmetric nonlinear electrodynamics
We explore dynamical features of the maximally symmetric nonlinear extension of classical electromagnetism, recently proposed in the literature as ``ModMax'' electrodynamics. This family of theories is the only one that preserves all the symmetries of Maxwell's theory, having applications in the study of regular black hole solutions and supersymmetry. The purpose of this article is three-fold. Firstly, we study the initial-value problem of ModMax and show, by means of a simple geometric criteri…

This https://arxiv.org/abs/2310.00407 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

On the limit theory of mean field optimal stopping with non-Markov dynamics and common noise
This paper focuses on a mean-field optimal stopping problem with non-Markov dynamics and common noise, inspired by Talbi, Touzi, and Zhang \cite{TalbiTouziZhang1,TalbiTouziZhang3}. The goal is to establish the limit theory and demonstrate the equivalence of the value functions between weak and strong formulations. The difference between the strong and weak formulations lies in the source of randomness determining the stopping time on a canonical space. In the strong formulation, the randomness …

A General Theory of Risk Sharing
Vasily Melnikov
https://arxiv.org/abs/2505.19276 https://arxiv.org/pdf/2505.19276

A General Theory of Risk Sharing
We introduce a new paradigm for risk sharing that generalizes earlier models based on discrete agents and extends them to allow for sharing risk within a continuum of agents. Agents are represented by points of a measure space and have potentially heterogeneous risk preferences modeled by risk measures. The existence of risk minimizing allocations is proved when constrained to satisfy economically convincing conditions. In the unconstrained case, we derive the dual representation of the value f…

This https://arxiv.org/abs/2110.06506 has been replaced.
link: https://scholar.google.com/scholar?q=a

Network analysis using Forman curvature and Shapley values on hypergraphs
In recent years, network models have become more complex with the development of big data. Therefore, more advanced network analysis is required. In this paper, we introduce a new quantitative measure named combinatorial evaluation, which combines the discrete geometry concept of Forman Ricci curvature and the game theory concept of the Shapley value. We elucidated the characteristics of combinatorial evaluation by proving several properties of this indicator. Furthermore, we demonstrated the u…

This https://arxiv.org/abs/2505.22371 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_sta…

Adaptive tail index estimation: minimal assumptions and non-asymptotic guarantees
A notoriously difficult challenge in extreme value theory is the choice of the number $k\ll n$, where $n$ is the total sample size, of extreme data points to consider for inference of tail quantities. Existing theoretical guarantees for adaptive methods typically require second-order assumptions or von Mises assumptions that are difficult to verify and often come with tuning parameters that are challenging to calibrate. This paper revisits the problem of adaptive selection of $k$ for the Hill…

This https://arxiv.org/abs/2505.20111 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Preference Disaggregation Analysis with Criteria Selection in a Regularization Framework
Limited by cognitive abilities, decision-makers (DMs) may struggle to evaluate decision alternatives based on all criteria in multiple criteria decision-making problems. This paper proposes an embedded criteria selection method derived from preference disaggregation technique and regularization theory. The method aims to infer the criteria and value functions used by the DM to evaluate decision alternatives. It measures the quality of criteria subsets by investigating both the empirical error (…

This https://arxiv.org/abs/2505.06369 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

Yang-Lee Quantum Criticality in Various Dimensions
The Yang-Lee universality class arises when imaginary magnetic field is tuned to its critical value in the paramagnetic phase of the $d<6$ Ising model. In $d=2$, this non-unitary Conformal Field Theory (CFT) is exactly solvable via the $M(2,5)$ minimal model. As found long ago by von Gehlen using Exact Diagonalization, the corresponding real-time, quantum critical behavior arises in the periodic Ising spin chain when the imaginary longitudinal magnetic field is tuned to its critical value from …

A note on the diversity Owen values
Songtao He, Erfang Shan, Xinyu Sun
https://arxiv.org/abs/2505.24171 https://arxiv.org/pdf/2505.24…

A note on the diversity Owen values
Béal et al. (Int J Game Theory 54, 2025) introduce the Diversity Owen value for TU-games with diversity constraints, and provide axiomatic characterizations using the axioms of fairness and balanced contributions. However, there exist logical flaws in the proofs of the uniqueness of these characterizations. In this note we provides the corrected proofs of the characterizations by introducing the null player for diversity games axiom. Also, we establish two alternative characterizations of the …

Adaptive tail index estimation: minimal assumptions and non-asymptotic guarantees
Johannes Lederer, Anne Sabourin, Mahsa Taheri
https://arxiv.org/abs/2505.22371

Adaptive tail index estimation: minimal assumptions and non-asymptotic guarantees
A notoriously difficult challenge in extreme value theory is the choice of the number $k\ll n$, where $n$ is the total sample size, of extreme data points to consider for inference of tail quantities. Existing theoretical guarantees for adaptive methods typically require second-order assumptions or von Mises assumptions that are difficult to verify and often come with tuning parameters that are challenging to calibrate. This paper revisits the problem of adaptive selection of $k$ for the Hill…

This https://arxiv.org/abs/2311.17270 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qfi…

Exponential Utility Maximization in a Continuous Time Gaussian Framework
In this work we study the continuous time exponential utility maximization problem in the framework of an investor who is informed about the price changes with a delay. This leads to a non-Markovian stochastic control problem. In the case where the risky asset is given by a Gaussian process (with some additional properties) we establish a solution for the optimal control and the corresponding value. Our approach is purely probabilistic and is based on the theory for Radon-Nikodym derivatives of…