arXiv subjects

Yanjun Zhou

Publications and source records attributed to Yanjun Zhou.

10 recordsLinked to original sources

arXiv2025

Bubbling wormholes and matrix models

The thermofield double state entangles two copies of a CFT via a sum over energy eigenstates and is dual to the two-sided eternal black hole. We explore an analogous construction using sums over gauge group representations of half-BPS Wilson loops in multiple copies of $U(N)$ $\mathcal{N}=4$ super Yang-Mills. These sums act as delta function-like operators that correlate the eigenvalues of the corresponding half-BPS matrix models. We suggest that the holographic duals are ''bubbling wormhole'' geometries: multi-covers of AdS$_5$ $\times S^5$ whose conformal boundary consists of multiple four-spheres intersecting on a common circle. We analyze the matrix model free energy, discuss its bulk interpretation, and study probe loops in these backgrounds.

hep-th↗

arXiv2025

Efficient Speculative Decoding for Llama at Scale: Challenges and Solutions

Speculative decoding is a standard method for accelerating the inference speed of large language models. However, scaling it for production environments poses several engineering challenges, including efficiently implementing different operations (e.g., tree attention and multi-round speculative decoding) on GPU. In this paper, we detail the training and inference optimization techniques that we have implemented to enable EAGLE-based speculative decoding at a production scale for Llama models. With these changes, we achieve a new state-of-the-art inference latency for Llama models. For example, Llama4 Maverick decodes at a speed of about 4 ms per token (with a batch size of one) on 8 NVIDIA H100 GPUs, which is 10% faster than the previously best known method. Furthermore, for EAGLE-based speculative decoding, our optimizations enable us to achieve a speed-up for large batch sizes between 1.4x and 2.0x at production scale.

cs.CL↗

arXiv2025

Near-extremal quantum cross-section for charged fields and superradiance

We study the scattering and absorption properties of charged scalar fields on a near-extremal Reissner-Nordstr\"om black hole background. We show that in this low-temperature regime the near-horizon throat experiences large quantum fluctuations, whose leading contribution is described by the one dimensional Schwarzian effective action, while the soft $U(1)$ gauge modes can only contribute to subleading order. We investigate the role of the leading quantum effects both inside and outside the superradiant regime. These effects result in an enhanced reflection coefficient within the superradiant regime, while causing a suppression in the non-superradiant regime. On the other hand, the absorption cross-section increases in both regimes. Additional physical features appear as kinks in the reflection coefficient and absorption cross-section plots, corresponding to the shutdown of absorption in the superradiant regime and of stimulated emission in the non-superradiant regime.

hep-th↗

arXiv2025

The Ephemeral Shadow: Hyperreal Beings in Stimulative Performance

The Ephemeral Shadow is an interactive art installation centered on the concept of "simulacrum," focusing on the reconstruction of subjectivity at the intersection of reality and virtuality. Drawing inspiration from the aesthetic imagery of traditional shadow puppetry, the installation combines robotic performance and digital projection to create a multi-layered visual space, presenting a progressively dematerialized hyperreal experience. By blurring the audience's perception of the boundaries between entity and image, the work employs the replacement of physical presence with imagery as its core technique, critically reflecting on issues of technological subjectivity, affective computing, and ethics. Situated within the context of posthumanism and digital media, the installation prompts viewers to contemplate: as digital technologies increasingly approach and simulate "humanity," how can we reshape identity and perception while safeguarding the core values and ethical principles of human subjectivity?

cs.HC↗

arXiv2024

An Interacting, Higher Derivative, Boundary Conformal Field Theory

We consider a higher derivative scalar field theory in the presence of a boundary and a classically marginal interaction. We first investigate the free limit where the scalar obeys the square of the Klein-Gordon equation. In precisely $d=6$ dimensions, modules generated by $d-2$ and $d-4$ dimensional primaries merge to form a staggered module. We compute the conformal block associated with this module and show that it is a generalized eigenvector of the Casimir operator. Next we include the effect of a classically marginal interaction that involves four scalar fields and two derivatives. The theory has an infrared fixed point in $d=6-{\epsilon}$ dimensions. We compute boundary operator anomalous dimensions and boundary OPE coefficients at leading order in the ${\epsilon}$ expansion for the allowed conformal boundary conditions.

hep-th↗

arXiv2014

The power-law TST reaction rate coefficient with tunneling correction

We study the TST reaction rate for the systems with power-law distributions. We derive the expressions of the reaction rate coefficient with tunneling correction, which strongly depends on the power-law parameter. The numerical results show that a small deviation from one in the parameter can result in a significant change in the rate coefficient, but only cause a small change in the tunneling correction. Thus the tunneling correction is not sensitive to the power-law distributions. As an application example, we take the hydrogen reaction to calculate the power-law reaction rate coefficient with the tunneling correction, the results of which with the parameter slightly different from one are in good agreement with all the experimental studies in temperature range 200~1000K.

physics.chem-ph↗

arXiv2014

The anomalous distributions and Soret coefficient in a nonequilibrium colloid system

The density distributions and Soret coefficient in a nonequilibrium colloidal system with nonuniform temperature are studied by the overdamped Langevin equation for Brownian motion in an inhomogeneous strong friction medium. Based on the relation between the temperature gradient, the interaction potential and the q-parameter in nonextensive statistics, We show that the colloidal particle density can be a function of the temperature and anomalously follows the noted alpha-distribution, or equivalently it can also be a function of the potential energy and follows Tsallis distribution. With the q-parameter we can establish a new formula of the Soret coefficient and thus, bridge the gap between the ideally theoretical Soret coefficient and available experiments.

cond-mat.soft↗

arXiv2014

Escape rate for the power-law distribution in low-to-intermediate damping

Escape rate in the low-to-intermediate damping connecting the low damping with the intermediate damping is established for the power-law distribution on the basis of flux over population theory. We extend the escape rate in the low damping to the low-to-intermediate damping, and get an expression for the power-law distribution. Then we apply the escape rate for the power-law distribution to the experimental study of the excited-state isomerization, and show a good agreement with the experimental value. The extra current and the improvement of the absorbing boundary condition are discussed.

cond-mat.stat-mech↗

arXiv2014

Kramers escape rate in overdamped systems with the power-law distribution

Kramers escape rate in the overdamped systems with the power-law distribution is studied. By using the mean first passage time, we derive the escape rate for the power-law distribution and obtain the Kramers' infinite barrier escape rate in this case. It is shown that the escape rate for the power-law distribution extends the Kramers' overdamped result to the relatively low barrier. Furthermore, we apply the escape rate for the power-law distribution to the unfolding of titin and show a better agreement with the experimental rate than the traditional escape rate.

cond-mat.stat-mech↗

arXiv2013

The mean first passage time in an energy-diffusion controlled regime with power-law distributions

Based on the mean first passage time (MFPT) theory, we derive the expression of the MFPT in the energy-diffusion controlled regime with a power-law distribution. We discuss the finite barrier effect (i.e. thermal energy is not small with respect to the potential barrier) and compare it with the Kramers infinite barrier result both in the power-law distribution and in a Maxwell-Boltzmann distribution. It is shown that the MFPT with the power-law distribution extends the Kramers' low damping result to the relatively low barrier. We pay attention to the energy-diffusion controlled regime which is of great interest in the context of Josephson junctions, and study how the power-law parameter affects the current distribution function in the experiment of Josephson junctions.

cond-mat.stat-mech↗