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Takayuki Hori

Publications and source records attributed to Takayuki Hori.

14 recordsLinked to original sources
arXiv2026

CuriosAI Submission to the CASTLE Challenge at EgoVis 2026

CASTLE 2026 asks 185 multiple-choice questions over 600+ hours of synchronized multi-view egocentric video. We explore two approaches on top of a shared multimodal preprocessing layer, including per-person timelines, speaker-resolved transcripts, and multi-VLM caption ensembles. Approach A, SVA: Search-Verify-Answer, is a three-stage pipeline that hierarchically narrows to a primary window, verifies sub-windows with a VLM under four anti-confabulation rules, and fuses evidence with an LLM judge under an evidence-priority hierarchy. Approach B, TMKG: Temporal-Multimodal-Knowledge-Graph, is the contrast: it builds a temporal multimodal knowledge graph, locates a primary cell via graph search, and produces the final answer with a single grounded VLM. SVA reaches a leaderboard accuracy of 0.50 and is our final challenge submission; TMKG reaches 0.35.

cs.CV↗
arXiv2025

Theory of Complex Particle without Extra Dimensions

Complex particle is a kind of bilocal particle having unexpected symmetry, which was proposed by the authour. In the present paper, we show that critical dimension of the complex particle in Minkowski spacetime is $D = 4$, while $D = 2, 4$ or $6$ are permitted in Euclid spacetime. The origin of the restriction to the dimension is the existence of tertiary constraint in the canonical theory, quantization of which leads to an eigenvalue equation having single-valued and bounded solutions only in particular dimension of spacetime. The derivation is based on a detailed analysis of Laplace-Beltrami operator on $S^{1,D-2}$ or $S^{D-1}$.

quant-ph↗
arXiv2025

CuriosAI Submission to the EgoExo4D Proficiency Estimation Challenge 2025

This report presents the CuriosAI team's submission to the EgoExo4D Proficiency Estimation Challenge at CVPR 2025. We propose two methods for multi-view skill assessment: (1) a multi-task learning framework using Sapiens-2B that jointly predicts proficiency and scenario labels (43.6 % accuracy), and (2) a two-stage pipeline combining zero-shot scenario recognition with view-specific VideoMAE classifiers (47.8 % accuracy). The superior performance of the two-stage approach demonstrates the effectiveness of scenario-conditioned modeling for proficiency estimation.

cs.CV↗
arXiv2025

Low-Barrier Dataset Collection with Real Human Body for Interactive Per-Garment Virtual Try-On

Existing image-based virtual try-on methods are often limited to the front view and lack real-time performance. While per-garment virtual try-on methods have tackled these issues by capturing per-garment datasets and training per-garment neural networks, they still encounter practical limitations: (1) the robotic mannequin used to capture per-garment datasets is prohibitively expensive for widespread adoption and fails to accurately replicate natural human body deformation; (2) the synthesized garments often misalign with the human body. To address these challenges, we propose a low-barrier approach for collecting per-garment datasets using real human bodies, eliminating the necessity for a customized robotic mannequin. We also introduce a hybrid person representation that enhances the existing intermediate representation with a simplified DensePose map. This ensures accurate alignment of synthesized garment images with the human body and enables human-garment interaction without the need for customized wearable devices. We performed qualitative and quantitative evaluations against other state-of-the-art image-based virtual try-on methods and conducted ablation studies to demonstrate the superiority of our method regarding image quality and temporal consistency. Finally, our user study results indicated that most participants found our virtual try-on system helpful for making garment purchasing decisions.

cs.GR↗
arXiv2019

Another Counter-Example to Dirac's Conjecture

Another counter-example to Dirac's Conjecture is presented, which resembles the Cawley model but is so modified as to include second class constraints. The arbitrary function in the general solution to the defining equations of momenta satisfies a non-linear differential equation. Dirac's conjecture is examined for some solutions to the equation.

physics.class-ph↗
arXiv2019

Restriction on Dirac's Conjecture

First class constraints in a canonical formalism of a gauge theory might generate transformations which map a state to its physically equivalent state. This is called Dirac's conjecture. There are two examples which may be candidates of counter-example of the conjecture. One is the toy model found by Cawley, and another is the bilocal model proposed by the author. A quantum analysis of the bilocal model shows that the model has the critical dimension of spacetime, which is surprisingly equal to four. The derivation, however, is based on the assumption that true symmetry of the system is generated by the first class constraints, which holds if Dirac's conjecture is satisfied. In the present paper we give detailed and mathematically rigorous analysis of Dirac's conjecture in general gauge theories, which involves new concept like semi-gauge invariance. We find the condition for the conjecture to hold. This is a set of equations for the generating function of the transformation, expressed in terms of Poisson brackets and M-brackets introduced in the paper. The above condition reduces the range of gauge theories where Dirac's conjecture holds. Along with the general prescription described in the paper we find that the bilocal model satisfies the above condition with some exceptions. Some examples are used to illustrate our method.

math-ph↗
arXiv2009

Relativistic Particle in Complex Space Time

A modified version of the bilocal particle is presented in terms of complex space time. Unusual constraint structure of the model is studied, and a new concept of the physical equivalence is proposed in accordance with Dirac's conjecture. It is found that in the quantum theory the physical state conditions are compatible with existence of eigenstates of momentum only when the dimension of space time is four. An example of scattering amplitude is calculated.

hep-th↗
arXiv2003

Quantization via Star Products

We study quantization via star products. We investigate a quantization scheme in which a quantum theory is described entirely in terms of the function space without reference to a Hilbert space, unlike the formulation employing the Wigner functions. The associative law plays an essential role in excluding the unwanted solutions to the stargen-value equation. This is demonstrated explicitly with the $D$-dimensional harmonic oscillator.

hep-th↗
arXiv2002

Moyal Quantization for Constrained System

We study the Moyal quantization for the constrained system. One of the purposes is to give a proper definition of the Wigner-Weyl(WW) correspondence, which connects the Weyl symbols with the corresponding quantum operators. A Hamiltonian in terms of the Weyl symbols becomes different from the classical Hamiltonian for the constrained system, which is related to the fact that the naively constructed WW correspondence is not one-to-one any more. In the Moyal quantization a geometrical meaning of the constraints is clear. In our proposal, the 2nd class constraints are incorporated into the definition of the WW correspondence by limiting the phasespace to the hypersurface. Even though we assume the canonical commutation relations in the formulation, the Moyal brackets between the Weyl symbols yield the same results as those for the constrained system derived by using the Dirac bracket formulation.

hep-th↗
arXiv1998

The Problem of Time in the Quantum Theory of Black Holes

We discuss the problem of time in spherically symmetric pure Einstein gravity with the cosmological term by using an exact solution to the Wheeler-DeWitt equation. A positive definite inner product is defined, based on the momentum constraint rather than the hamiltonian constraint. A natural notion of time is introduced via the Heisenberg equation. This notion enables one to reproduce the time-time component of the classical metric. Non-Hermiticity of the hamiltonian is essential in the definition of time.

hep-th↗
arXiv1996

BRS Cohomology of a Bilocal Model

We present a model in which a gauge symmetry of a field theory is intrinsic in the geometry of an extended space time itself. A consequence is that the dimension of our space time is restricted through the BRS cohomology. If the Hilbert space is a dense subspace of the space of all square integrable $C^{\infty}$ functions, the BRS cohomology classes are nontrivial only when the dimension is two or four.

hep-th↗
arXiv1993

A Bilocal Field Theory in Four Dimensions

A bilocal field theory having Möbius gauge invariance is proposed. In four dimensions there exists a zero momentum state of the first quantized model, which belongs to a non-trivial BRS cohomology class. A field theory lagrangian having a gauge invariance only in four dimensions is constructed.

hep-th↗
arXiv1993

Wave Functional of Quantum Black Holes in Two Dimensions

The wheeler-DeWitt method is applied to the quantization of the 1 + 1 dimensional dilaton gravity coupled with the conformal matter fields. Exact solutions to the WD equations are found, which are interpreted as right(left)-moving black holes.

hep-th↗