A thermodynamical treatment of a massless scalar field (a photon) confined to a fractal spatial manifold leads to an equation of state relating pressure to internal energy, PV(s) = U/d(s), where d(s) is the spectral dimension and V(s) defines the "spectral volume." For regular manifolds, V(s) coincides with the usual geometric spatial volume, but on a fractal this is not necessarily the case. This is further evidence that on a fractal, momentum space can have a different dimension than position space. Our analysis also provides a natural definition of the vacuum (Casimir) energy of a fractal. We suggest ways that these unusual properties might be probed experimentally.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.105.230407 | DOI Listing |
ACS Nano
January 2025
Conte Center for Polymer Research, Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
Bottlebrush block copolymers (BBCPs) are a unique class of materials that contain a backbone with densely grafted and chemically distinct polymeric side chains. The nonlinear architecture of BBCPs provides numerous degrees of freedom in their preparation, including control over key parameters such as grafting density, side chain length, block arrangement, and overall molecular weight. This uniquely branched structure provides BBCPs with several important distinctions from their linear counterparts, including sterically induced side chain and backbone conformations, rapid and large self-assembled nanostructures, and reduced or eliminated entanglement effects (assuming sufficient grafting density and that the molecular weight of the side chains is below their respective entanglement molecular weight).
View Article and Find Full Text PDFACS Photonics
January 2025
Center for Nanophotonics, AMOLF, Science Park 104, XG Amsterdam 1098, the Netherlands.
We present a complete framework of stochastic thermodynamics for a single-mode linear optical cavity driven on resonance. We first show that the steady-state intracavity field follows the equilibrium Boltzmann distribution. The effective temperature is given by the noise variance, and the equilibration rate is the dissipation rate.
View Article and Find Full Text PDFJ Chem Phys
January 2025
School of Chemistry, Beihang University, Beijing 100191, China.
Dynamic density functional theory (DDFT) is a fruitful approach for modeling polymer dynamics, benefiting from its multiscale and hybrid nature. However, the Onsager coefficient, the only free parameter in DDFT, is primarily derived empirically, limiting the accuracy and broad application of DDFT. Herein, we propose a machine learning-based, bottom-up workflow to directly extract the Onsager coefficient from molecular simulations, circumventing partly heuristic assumptions in traditional approaches.
View Article and Find Full Text PDFMycopathologia
January 2025
Teikyo University Institute of Medical Mycology (TIMM), 359 Otsuka, Hachioji, Tokyo, 192-0395, Japan.
We describe a novel Malassezia species named Malassezia polysorbatinonusus, isolated from a Japanese patient with seborrheic dermatitis. The internal transcribed spacer (ITS) region of the isolate (LSEM 4845) were only 94.7% identical to those of M.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Key Laboratory of Hunan Province on Information Photonics and Freespace Optical Communications, School of Physics and Electronics Science, Hunan Institute of Science and Technology, Yueyang 414006, People's Republic of China.
Constructing van der Waals heterostructures (vdWHs) has emerged as an attractive strategy to combine and enhance the optoelectronic properties of stacked materials. Herein, by means of first-principles calculations, we investigate the geometric and electronic structures of the AlP/CsBiICl vdWH as well as its tunable band structure an external electric field. The AlP/CsBiICl vdWH is structurally and thermodynamically stable due to the low binding energy and the small energy fluctuation at room temperature.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!