arXiv subjects

Viola Zixin Zhao

Publications and source records attributed to Viola Zixin Zhao.

3 recordsLinked to original sources

arXiv2026

Odd Diffusion in Three-Dimensional Isotropic Media

Odd diffusion is a hallmark of chiral active matter, generating currents transverse to density gradients. Existing theories rely on a linear antisymmetric transport coefficient that exists only in two dimensions, raising the question of whether odd diffusion can occur in isotropic three-dimensional systems. Here we show that such transport is possible through a nonlinear constitutive law. Symmetry considerations reveal that the three-dimensional Levi-Civita tensor permits a leading order isotropic odd current at second order in the density gradient expansion and only in multicomponent systems. The resulting transport generates boundary-driven rotational currents, finite vorticity, and enstrophy despite the absence of external torques or preferred directions. We show how such a constitutive law derives from a microscopic model of particles interacting through nonreciprocal three-body forces using the Dean--Kawasaki coarse-graining procedure. These results establish a minimal framework for odd transport in isotropic three dimensions.

cond-mat.soft↗

arXiv2026

Interpreting the Synchronization Gap: The Hidden Mechanism Inside Diffusion Transformers

Recent theoretical models of diffusion processes, conceptualized as coupled Ornstein-Uhlenbeck systems, predict a hierarchy of interaction timescales, and consequently, the existence of a synchronization gap between modes that commit at different stages of the reverse process. However, because these predictions rely on continuous time and analytically tractable score functions, it remains unclear how this phenomenology manifests in the deep, discrete architectures deployed in practice. In this work, we investigate how the synchronization gap is mechanistically realized within pretrained Diffusion Transformers (DiTs). We construct an explicit architectural realization of replica coupling by embedding two generative trajectories into a joint token sequence, modulated by a symmetric cross attention gate with variable coupling strength g. Through a linearized analysis of the attention difference, we show that the replica interaction decomposes mechanistically. We empirically validate our theoretical framework on a pretrained DiT-XL/2 model by tracking commitment and per layer internal mode energies. Our results reveal that: (1) the synchronization gap is an intrinsic architectural property of DiTs that persists even when external coupling is turned off; (2) as predicted by our spatial routing bounds, the gap completely collapses under strong coupling; (3) the gap is strictly depth localized, emerging sharply only within the final layers of the Transformer; and (4) global, low frequency structures consistently commit before local, high frequency details. Ultimately, our findings provide a mechanistic interpretation of how Diffusion Transformers resolve generative ambiguity, isolating speciation transitions to the terminal layers of the network.

cs.LG↗

arXiv2025

Notes on the Quantization of Tropological Yang Mills Theory

We continue our investigation into anisotropic topological field theories which arise from a tropical limit of conventional isotropic topological field theories. We analyze both the TBF theory and the tropical analogue of 2D topological Yang-Mills theory (TrYM) through a direct path integral calculation which probes a deformed analytic torsion and also through canonical quantization. The explicit construction of the Hilbert space of TrYM theory demonstrates that the TrYM theory provides an example of a solvable field theory where anisotropy properties and topological invariance can simultaneously hold. We show that the partition function has an asymptotic limit, which verifies that the dimension of the moduli space of tropicalized flat connection on a Riemann surface of genus $g>1$ is precisely given by $(g-1) \operatorname{rank}(\mathfrak{g})$. We show that the interpretation of this result is that the random matrix model associated to the U$(N)$ TrYM is in fact a novel random matrix theory whose integration space is still the same space of hermitian matrices (similar to a GUE) however the Dyson index matches that of a GOE consistent with the usual intuition that tropicalization reduces down complex objects to their real counterparts.

hep-th↗