Results 91 to 100 of about 32,582 (169)

Aspects of perturbative unitarity

, 2016
We reconsider perturbative unitarity in quantum field theory and upgrade several arguments and results. The minimum assumptions that lead to the largest time equation, the cutting equations and the unitarity equation are identified.
Anselmi, Damiano
core   +1 more source

Spinors and Voros star-product for Group Field Theory: First Contact

, 2011
In the context of non-commutative geometries, we develop a group Fourier transform for the Lie group SU(2). Our method is based on the Schwinger representation of the Lie algebra su(2) in terms of spinors. It allows us to prove that the non-commutative R^
Dupuis, Maité, Girelli, Florian, Livine, Etera R.   +2 more
core   +1 more source

THz‐Driven Coherent Phonon Fingerprints of Hidden Symmetry Breaking in 2D Layered Hybrid Perovskites

Advanced Materials, Volume 38, Issue 4, 16 January 2026.
Intense THz pulses are employed to drive coherent phonons in 2D Ruddlesden‐Popper hybrid metal‐halide perovskites (HOIPs) from the (PEA)2(MA)n‐1PbnI3n+1 family, revealing mode‐selective spectroscopic signatures of inversion symmetry breaking in those nominally centrosymmetric materials. These findings provide a handle to decode nonlinear phonon driving
Joanna M. Urban, Michael S. Spencer, Maximilian Frenzel, Gaëlle Trippé‐Allard, Marie Cherasse, Charlotte Berrezueta‐Palacios, Prakriti P. Joshi, Alexander P. Fellows, Olga Minakova, Eduardo B. Barros, Luca Perfetti, Stephanie Reich, Martin Wolf, Emmanuelle Deleporte, Sebastian F. Maehrlein   +14 more
wiley   +1 more source

Alternative Method for Determining the Feynman Propagator of a Non-Relativistic Quantum Mechanical Problem

Symmetry, Integrability and Geometry: Methods and Applications, 2007
A direct procedure for determining the propagator associated with a quantum mechanical problem was given by the Path Integration Procedure of Feynman. The Green function, which is the Fourier Transform with respect to the time variable of the propagator,
Marcos Moshinsky, Emerson Sadurní, Adolfo del Campo   +2 more
doaj  

On time-dependent AdS/CFT

, 2003
We clarify aspects of the holographic AdS/CFT correspondence that are typical of Lorentzian signature, to lay the foundation for a treatment of time-dependent gravity and conformal field theory phenomena.
C.P. Herzog, D.T. Son, E. Witten, E. Witten, E.C. Titchmarsh, I. Gel'fand, I.R. Klebanov, J.M. Maldacena, J.M. Maldacena, J.S. Schwinger, Jan Troost, K. Gawedzki, L. Mezincescu, L. Susskind, L.V. Keldysh, M. Abramowitz, M. Bertola, M. Reed, M. Spradlin, N. Birrell, P. Breitenlohner, P. Minces, P. Morse, P.M. Bakshi, P.M. Bakshi, U.H. Danielsson, V. Balasubramanian, Y. Brychkov, Yuji Satoh   +28 more
core   +1 more source

Ponzano-Regge model revisited III: Feynman diagrams and Effective field theory

, 2005
We study the no gravity limit G_{N}-> 0 of the Ponzano-Regge amplitudes with massive particles and show that we recover in this limit Feynman graph amplitudes (with Hadamard propagator) expressed as an abelian spin foam model.
Akhmedov E T, Barrett J W, Barrett J W, Barrett J W Garcia-Islas J M Martins J F, Davids S, Etera R Livine, Freidel L, Freidel L, Freidel L, Freidel L, Freidel L Louapre D, Freidel L Noui K Roche P, Freidel L Starodubtsev A, Kosinski P Maslanka P Lukierski J Sitarz A, Kowalski-Glikman J, Laurent Freidel, Madore J, Majid S, Meusburger C, Noui K, Oriti D, Perez A, Ponzano G, Reisenberger M P, Rovelli C, Smolin L, Weinberg S   +26 more
core   +2 more sources

CONDITIONAL GENERALIZED FOURIER-FEYNMAN TRANSFORM OF FUNCTIONALS IN A FRESNEL TYPE CLASS [PDF]

Communications of the Korean Mathematical Society, 2011
In this paper we dene the concept of a conditional generalized Fourier-Feynman transform on very general function space [0, T]. We then establish the existence of the conditional generalized Fourier-Feynman transform for functionals in a Fresnel type class. We also obtain several results involving the conditional transform.
openaire   +1 more source

Fractional-Time Schr\"odinger Equation: Fractional Dynamics on a Comb

, 2011
The physical relevance of the fractional time derivative in quantum mechanics is discussed. It is shown that the introduction of the fractional time Scr\"odinger equation (FTSE) in quantum mechanics by analogy with the fractional diffusion $\frac{\prt ...
Iomin, Alexander
core   +1 more source

Functional determinants for false vacuum decay

Journal of High Energy Physics
We derive simple expressions to regularise functional determinants from fluctuations of fields with spin 0, 1/2, and 1. These are important for the precise dimensionful determination of false vacuum decay rates.
Pietro Baratella, Miha Nemevšek, Yutaro Shoji, Katarina Trailović, Lorenzo Ubaldi   +4 more
doaj   +1 more source

FOURIER-FEYNMAN TRANSFORM AND CONVOLUTION OF FOURIER-TYPE FUNCTIONALS ON WIENER SPACE [PDF]

East Asian mathematical journal, 2013
Abstract. We develop a Fourier-Feynman theory for Fourier-type func-tionals k F and [F on Wiener space. We show that Fourier-Feynmantransform and convolution of Fourier-type functionals exist. We alsoshow that the Fourier-Feynman transform of the convolution product ofFourier-type functionals is a product of Fourier-Feynman transforms ofeach ...
openaire   +1 more source