arXiv subjects

Herve Zwirn

Publications and source records attributed to Herve Zwirn.

10 recordsLinked to original sources

arXiv2026

Misunderstanding Convivial Solipsism: the Necessity of a Perspectival Logic

Convivial Solipsism is easily misunderstood. Because it denies the absoluteness of observed events while preserving the universality of quantum mechanics, it invites objections that are often formulated in a classical, non-perspectival language. Such objections appear powerful only because they smuggle back into the discussion the very assumptions that Convivial Solipsism rejects. This article reconstructs a family of misunderstandings that arise in discussions of Convivial Solipsism, especially in connection with Wigner's friend and extended Wigner's friend scenarios. The aim is not merely defensive. The objections are useful because they identify the conceptual discipline required by any interpretation that takes non-absolute facts seriously. The central claim is that observational facts must be indexed to perspectives. A statement such as "the friend saw outcome A" is not a complete factual statement within Convivial Solipsism. It must be reformulated as "from the friend's perspective, the friend saw outcome A" or "from Wigner's perspective, the friend reported outcome B." The mistake consists in removing these indices and then treating the resulting expressions as if they belonged to a single global factual domain. This leads to apparent contradictions and to false dilemmas concerning consciousness, communication, other minds, and intersubjectivity. When that is taken into account, it appears that Convivial Solipsism is not a retreat into psychological solipsism, but a discipline of perspectival discourse. It is also shown that perspectival logic stands to classical logic as the quantum calculus of probability stands to Kolmogorovian probability theory.

quant-ph↗

arXiv2026

Is Quantum Mechanics Universal? EWF Experiments and Non Absoluteness of Events

Extended Wigner-type experiments reveal a fundamental tension between the universality of quantum mechanics, the absoluteness of observed events, and the structure of physical reality. While recent no-go theorems suggest that these assumptions cannot be jointly maintained, their interpretation remains unclear. In particular, the claim that events are not absolute is often left at the level of an interpretive slogan, without a precise conceptual formulation. In this paper, we analyse the conceptual structure underlying these results and show that the non-absoluteness of events requires a precise formulation in order to avoid ambiguity. We argue that many existing approaches fail to provide such a formulation, either by implicitly reintroducing observer-independent structure or by leaving key notions underdetermined. Within this framework, Convivial Solipsism offers a coherent and fully articulated account of non-absolute events, preserving the universality of quantum mechanics while avoiding the need for a global viewpoint. We show in particular that this approach resolves the apparent conflict between perspectival outcomes and scientific intersubjectivity. These results suggest that scientific objectivity does not rely on observer-independent facts, but on the internal coherence of perspectival structures.

quant-ph↗

arXiv2025

Are Events Absolute?

The Wigner's Friend thought experiment stands as one of the most intellectually provocative and challenging conceptual puzzles in quantum mechanics. It compels us to confront profound questions concerning the fundamental nature of reality, the very act of observation, and the possible role that consciousness might play within the quantum measurement process. This article gives a general presentation, beginning with Eugene Wigner's seminal proposal of the original thought experiment. In this paper, we explore its initial implications, which shook the foundations of classical physics, and then progress to an examination of the recent theoretical advancements and the ingenious extended versions of the experiment. The recent versions seem to imply that it is no more possible to consider events as absolute.

quant-ph↗

arXiv2024

Quantum Decision Theory

In this article, we propose to use the formalism of quantum mechanics to describe and explain the so-called "abnormal" behaviour of agents in certain decision or choice contexts. The basic idea is to postulate that the preferences of these agents are indeterminate (in the quantum sense of the term) before the choice is made or the decision is taken. An agent's state before the decision is represented by a superposition of potential preferences. The decision is assimilated to a measure of the agent's state and leads to a projection of the state onto one of the particular preferences. We therefore consider that uncertainty about preferences is not linked to incomplete information but to essential indeterminacy. We explore the consequences of these hypotheses on the usual concepts of decision theory and apply the formalism to the problem of the so-called "framing" effect.

physics.soc-ph↗

arXiv2024

Is Intersubjectivity Proven? A Reply to Khrennikov and to QBists

In two recent papers Khrennikov uses what he calls Ozawa intersubjectivity theorem to claim that intersubjectivity is necessarily verified in quantum mechanics and to criticize QBism and more generally all interpretations that are perspectival. In agreement with two previous QBist papers, I explain here why Khrennikov proof is not valid but in contrast with one of these papers, I criticize the way intersubjectivity is dealt with in QBism.

quant-ph↗

arXiv2023

Convivial Solipsism as a maximally perspectival interpretation

A classification of different interpretations of the quantum formalism is examined and the concept of perspectival interpretation is presented. A perspectival interpretation implies that the truth is relative to the observer. The degree to which QBism and Convivial Solipsism are perspectival is examined and Convivial Solipsim is shown to be perspectival at a higher degree than QBism or at least than the QBism founders version.

quant-ph↗

arXiv2016

The Measurement Problem: Decoherence and Convivial Solipsism

The problem of measurement is often considered as an inconsistency inside the quantum formalism. Many attempts to solve (or to dissolve) it have been made since the inception of quantum mechanics. The form of these attempts depends on the philosophical position that their authors endorse. I will review some of them and analyze their relevance. The phenomenon of decoherence is often presented as a solution lying inside the pure quantum formalism and not demanding any particular philosophical assumption. Nevertheless, a widely debated question is to decide between two different interpretations. The first one is to consider that the decoherence process has the effect to actually project a superposed state into one of its classically interpretable component, hence doing the same job as the reduction postulate. For the second one, decoherence is only a way to show why no macroscopic superposed state can be observed, so explaining the classical appearance of the macroscopic world, while the quantum entanglement between the system, the apparatus and the environment never disappears. In this case, explaining why only one single definite outcome is observed remains to do. In this paper, I examine the arguments that have been given for and against both interpretations and defend a new position, the "Convivial Solipsism" , according to which the outcome that is observed is relative to the observer, different but in close parallel to the Everett's interpretation and sharing also some similarities with Rovelli's relational interpretation and quantum bayesianism. I also show how "Convivial Solipsism" can help getting a new standpoint about the EPR paradox providing a way out of the standard dilemma that is having to choose between abandoning either realism or locality.

quant-ph↗

arXiv2013

Computational Irreducibility and Computational Analogy

In a previous paper, we provided a formal definition for the concept of computational irreducibility (CIR), i.e. the fact for a function f from N to N that it is impossible to compute f(n) without following approximately the same path than computing successively all the values f(i) from i=1 to n. Our definition is based on the concept of E Turing machines (for Enumerating Turing Machines) and on the concept of approximation of E Turing machines for which we also gave a formal definition. We precise here these definitions through some modifications intended to improve the robustness of the concept. We introduce then a new concept: the Computational Analogy and prove some properties of computationally analog functions. Computational Analogy is an equivalence relation which allows partitioning the set of computable functions in classes whose members have the same properties regarding to their computational irreducibility and their computational complexity.

cs.CC↗

arXiv2012

Unpredictability and Computational Irreducibility

We explore several concepts for analyzing the intuitive notion of computational irreducibility and we propose a robust formal definition, first in the field of cellular automata and then in the general field of any computable function f from N to N. We prove that, through a robust definition of what means "to be unable to compute the nth step without having to follow the same path than simulating the automaton or the function", this implies genuinely, as intuitively expected, that if the behavior of an object is computationally irreducible, no computation of its nth state can be faster than the simulation itself.

cs.CC↗

arXiv2007

Type Indeterminacy: A Model for the KT(Kahneman-Tversky)-Man

In this paper we propose to use elements of the mathematical formalism of Quantum Mechanics to capture the idea that agents' preferences, in addition to being typically uncertain, can also be indeterminate. They are determined (i.e., realized, and not merely revealed) only when the action takes place. An agent is described by a state that is a superposition of potential types (or preferences or behaviors). This superposed state is projected (or "collapses") onto one of the possible behaviors at the time of the interaction. In addition to the main goal of modelling uncertainty of preferences that is not due to lack of information, this formalism seems to be adequate to describe widely observed phenomena of noncommutativity in patterns of behavior. We explore some implications of our approach in a comparison between classical and type indeterminate rational choice behavior. The potential of the approach is illustrated in two examples.

physics.soc-ph↗