activity
20132026
most citedReflection ranks and ordinal analysis

11 citations · 28 across the 30 of their papers we have counts for

collaborators

37 papers

cs.SD2026

ACR-Net: Mitigating Semantic Dominance via Contrastive Acoustic-Semantic Decoupling

Mengke Zhang, Yanda Shao, Tianhe Wu +1

Speech Emotion Recognition (SER) models and Audio LLMs fail when vocal tone contradicts textual semantics. Extensive training on congruent data engenders a rigid semantic prior, ca…

math.LO2026

Infinitary provability logic

Mojtaba Mojtahedi, Fedor Pakhomov, Giovanni Soldà

Gödel-Löb provability logic $\GL$ is a propositional modal system that on one hand enjoys completeness with respect to conversely well-founded Kripke frames and on the other hand c…

math.LO2026

Lévy-Montague reflection is -conservative over

Fedor Pakhomov

We study a Lévy-Montague reflection scheme in second-order arithmetic: for each formula , the scheme asserts that every set belongs to a countable coded -model…

math.LO2026

Speedups for Presburger Arithmetic and Real Closed Fields

Fedor Pakhomov, Julien Daoud

In the present paper, we consider Presburger arithmetic PrA and the theory of real closed fields RCF. Due to quantifier elimination in these theories, there are two kinds of natura…

math.LO2026

Well-quasi-orders on finite trees and transfinite sequences

Alakh Dhruv Chopra, Fedor Pakhomov

We study the well-quasi-order (wqo) consisting of the set of finite trees with leaf labels coming from an arbitrary wqo , ordered by tree homomorphisms which respect the order o…

math.LO2025

Generalized Higman's Theorem and iterated ideals

Fedor Pakhomov, Giovanni Soldà

Generalized Higman's Theorem is the direct counterpart of Higman's Theorem that asserts the closure of the class of \emph{better} quasi-orders, instead of the class of \emph{well}…

math.LO2025

Ranking theories via encoded -models

Hanul Jeon, Patrick Lutz, Fedor Pakhomov +1

Ranking theories according to their strength is a recurring motif in mathematical logic. We introduce a new ranking of arbitrary (not necessarily recursively axiomatized) theories…

math.LO2024

Automatic structures and the problem of natural well-orderings

Lev D. Beklemishev, Fedor N. Pakhomov

We explore the idea of using automatic and similar kind of presentations of structures to deal with the conceptual problem of natural proof-theoretic ordinal notations. We conclude…

math.LO2024

On Nash-Williams' Theorem regarding sequences with finite range

Fedor Pakhomov, Giovanni Soldà

The famous theorem of Higman states that for any well-quasi-order (wqo) the embeddability order on finite sequences over is also wqo. In his celebrated 1965 paper, Nash-Wil…

math.LO2024

Feferman's completeness theorem

Fedor Pakhomov, Michael Rathjen, Dino Rossegger

Feferman proved in 1962 that any arithmetical theorem is a consequence of a suitable transfinite iteration of full uniform reflection of . This result is commonly know…

math.LO2024

The Logic of Correct Models

Juan Pablo Aguilera, Fedor Pakhomov

For each , let mean "the sentence is true in all -correct transitive sets." Assuming Gödel's axiom , we prove the following graded varian…

math.LO2023

Provable better quasi orders

Anton Freund, Alberto Marcone, Fedor Pakhomov +1

It has recently been shown that fairly strong axiom systems such as cannot prove that the antichain with three elements is a better quasi order (). I…

math.LO2023★ 1 cited

The logical strength of minimal bad arrays

Anton Freund, Fedor Pakhomov, Giovanni Soldà

This paper studies logical aspects of the notion of better quasi order, which has been introduced by C. Nash-Williams (Mathematical Proceedings of the Cambridge Philosophical Socie…

math.LO2022

How to escape Tennenbaum's theorem

Fedor Pakhomov

We construct a theory definitionally equivalent to first-order Peano arithmetic PA and a non-standard computable model of this theory. The same technique allows us to construct a t…

math.LO2022

Linear Orders in Presburger Arithmetic

Fedor Pakhomov, Alexander Zapryagaev

We prove the linear orders first-order definable in the standard model $(\ZZ;<,+)$ of Presburger arithmetic are exactly those that are $(\ZZ;<,+)$-definably embeddable into the lex…

math.LO2022

There are no minimal essentially undecidable Theories

Fedor Pakhomov, Juvenal Murwanashyaka, Albert Visser

We show that there is no theory that is minimal with respect to interpretability among recursively enumerable essentially undecidable theories.

math.CO2022

Generalized fusible numbers and their ordinals

Alexander I. Bufetov, Gabriel Nivasch, Fedor Pakhomov

Erickson defined the fusible numbers as a set of reals generated by repeated application of the function . Erickson, Nivasch, and Xu showed that $\mat…

math.LO2022

Functorial Fast-Growing Hierarchies

J. P. Aguilera, F. Pakhomov, A. Weiermann

Fast-growing hierarchies are sequences of functions obtained through various processes similar to the ones that yield multiplication from addition, exponentiation from multiplicati…

math.LO2021

Arithmetical and Hyperarithmetical Worm Battles

David Fernández-Duque, Joost J. Joosten, Fedor Pakhomov +2

Japaridze's provability logic has one modality for each natural number and has been used by Beklemishev for a proof theoretic analysis of Peano aritmetic and rel…

math.LO2021

The Consequences of a Theory

Juan P. Aguilera, Fedor Pakhomov

We develop the abstract framework for a proof-theoretic analysis of theories with scope beyond ordinal numbers, resulting in an analog of Ordinal Analysis aimed at the study of the…

math.LO2021

Finitely Axiomatized Theories Lack Self-Comprehension

Fedor Pakhomov, Albert Visser

In this paper we prove that no consistent finitely axiomatized theory one-dimensionally interprets its own extension with predicative comprehension. This constitutes a result with…

math.LO2021

Reducing -model reflection to iterated syntactic reflection

Fedor Pakhomov, James Walsh

In mathematical logic there are two seemingly distinct kinds of principles called "reflection principles." Semantic reflection principles assert that if a formula holds in the whol…

math.LO2020

Multi-Dimensional Interpretations of Presburger Arithmetic in Itself

Fedor Pakhomov, Alexander Zapryagaev

Presburger Arithmetic is the true theory of natural numbers with addition. We study interpretations of Presburger Arithmetic in itself. The main result of this paper is that all se…

math.LO2019★ 4 cited

A weak set theory that proves its own consistency

Fedor Pakhomov

In the paper we introduce a weak set theory . A formalization of arithmetic on finite von Neumann ordinals gives an embedding of arithmetical language into this t…