Results 41 to 50 of about 5,789 (259)

UNITARY MATRIX MODELS AND 2D QUANTUM GRAVITY [PDF]

Modern Physics Letters A, 1992
The KdV and modified KdV integrable hierarchies are shown to be different descriptions of the same 2D gravitational system — open-closed string theory. Non-perturbative solutions of the multicritical unitary matrix models map to non-singular solutions of the 'renormalization group' equation for the string susceptibility, [Formula: see text].
Dalley, S., Johnson, C. V., Morris, T. R., Wätterstam, A.   +3 more
openaire   +2 more sources

A Matrix Model for Flat Space Quantum Gravity

Journal of High Energy Physics, 2023
Abstract We take a step towards the non-perturbative description of a two-dimensional dilaton-gravity theory which has a vanishing cosmological constant and contains black holes. This is done in terms of a double-scaled Hermitian random matrix model which non-perturbatively computes the partition function for the asymptotic Bondi ...
Kar, Arjun, Lamprou, Lampros, Marteau, Charles, Rosso, Felipe   +3 more
openaire   +4 more sources

Quantum singularities in a model of f(R) gravity [PDF]

The European Physical Journal C, 2012
The formation of a naked singularity in a model of f(R) gravity having as source a linear electromagnetic field is considered in view of quantum mechanics. Quantum test fields obeying the Klein-Gordon, Dirac and Maxwell equations are used to probe the classical timelike naked singularity developed at r=0.
Gürtuğ, Özay, Tahamtan, Tayebeh, Gürtuğ, Özay   +2 more
openaire   +5 more sources

One‐Step Curcumin‐Mediated Multiphoton Lithography for Bioactive 3D Scaffolds

Advanced Functional Materials, EarlyView.
Curcumin‐mediated multiphoton lithography enables one‐step fabrication of highly architected complex gelatin methacryloyl scaffolds by exploiting curcumin as a multifunctional bioactive photoinitiator. The resulting 3D structures support mesenchymal stem cell adhesion, proliferation, and migration, while exhibiting dual antibacterial activity through ...
Myrto Charitaki, Michalis Stavrou, Chrysanthi Pinelopi Apostolidou, Elmina Kabouraki, David Gray, Anna Mitraki, Anthi Ranella, Maria Farsari   +7 more
wiley   +1 more source

Testing a (Stringy) Model of Quantum Gravity [PDF]

, 2001
I discuss a specific model of space-time foam, inspired by the modern non-perturbative approach to string theory (D-branes). The model views our world as a three brane, intersecting with D-particles that represent stringy quantum gravity effects, which can be real or virtual.
openaire   +2 more sources

A Lightweight, 3D‐Printable, Low‐Cost, “One‐Click” Dorsal Skin Window for High‐Quality Long‐Term Multimodal Subcutaneous Tumor Imaging

Advanced Healthcare Materials, EarlyView.
An innovative, lightweight 3D‐printed skinfold chamber system is presented for long‐term intravital imaging. This affordable, biocompatible platform simplifies surgical implantation and allows high‐resolution, multimodal visualization of the tumor microenvironment for up to four weeks.
Iván Cortés Domínguez, Xabier Morales Urteaga, Maider Esparza, Lucía Grande, Ainhoa Urbiola, Cristina Ederra, Tomas Muñoz Santoro, Beatrice Pinci, Alvaro Teijeira, Carlos Ortiz de Solórzano   +9 more
wiley   +1 more source

Spin foam models of Riemannian quantum gravity [PDF]

Classical and Quantum Gravity, 2002
Using numerical calculations, we compare three versions of the Barrett-Crane model of 4-dimensional Riemannian quantum gravity. In the version with face and edge amplitudes as described by De Pietri, Freidel, Krasnov, and Rovelli, we show the partition function diverges very rapidly for many triangulated 4-manifolds.
Baez, John C., Christensen, J. Daniel, Halford, Thomas R., Tsang, David C.   +3 more
openaire   +3 more sources

Decoupling Photochemical and Photothermal Effects Using Molecular Motors Enables Fast, Intelligent, and Life‐Like Motions in Soft Materials

Advanced Materials, EarlyView.
A light‐responsive liquid crystal (LC) polymer network integrating molecular rotary motors and photothermal converters enables the decoupling of photochemical and photothermal effects. Selective wavelength activation allows orthogonal control over persistent shape encoding and fast reversible motion, enabling programmable soft robots capable of complex
Guiying Long, Jinyu Sheng, Alexander Ryabchun, Ben L. Feringa   +3 more
wiley   +1 more source

Spikes and spines in 4D Lorentzian simplicial quantum gravity

Journal of High Energy Physics
Simplicial approaches to quantum gravity such as quantum Regge calculus and spin foams include configurations where bulk edges can become arbitrarily large while the boundary edges are kept small.
Johanna Borissova, Bianca Dittrich, Dongxue Qu, Marc Schiffer   +3 more
doaj   +1 more source

Matrix quantization of gravitational edge modes

Journal of High Energy Physics, 2023
Gravitational subsystems with boundaries carry the action of an infinite-dimensional symmetry algebra, with potentially profound implications for the quantum theory of gravity.
William Donnelly, Laurent Freidel, Seyed Faroogh Moosavian, Antony J. Speranza   +3 more
doaj   +1 more source