Results 131 to 140 of about 11,120,519 (277)

Renormalization of the 2PI Hartree-Fock approximation on de Sitter background in the broken phase

, 2012
The infrared effects for light minimally coupled scalar fields with quartic self-interaction in de Sitter space is investigated using the 2PI effective action formalism.
Arai, Takashi
core   +1 more source

Nonperturbative effects of vacuum energy on the recent expansion of the universe [PDF]

, 1999
We show that the vacuum energy of a free quantized field of very low mass can significantly alter the recent expansion of the universe. The effective action of the theory is obtained from a non-perturbative sum of scalar curvature terms in the propagator.
L. Parker, A. Raval
semanticscholar   +1 more source

Nonperturbative Effects on the String World Sheet (Ii)

Nuclear Physics B, 1987
We show that the space-time superpotential, which is known to receive no string theoretic corrections in finite orders in α′, is modified by world-sheet instantons. This has a number of interesting consequences for the physics of compactification schemes which lead to low-energy supersymmetry.
Xiao-Gang Wen, Nathan Seiberg, Nathan Seiberg, Edward Witten, Michael Dine, Michael Dine   +5 more
openaire   +2 more sources

T‐Symmetry in String Geometry Theory

Advances in High Energy Physics, Volume 2025, Issue 1, 2025.
String geometry theory is one of the candidates of nonperturbative formulation of string theory. In this paper, we have shown that dimensionally reduced string geometry theories have what we call T‐symmetry. In the case of the dimensional reduction in space‐like directions, the T‐symmetry transformation gives the T‐dual transformation between the Type ...
Matsuo Sato, Taiki Tohshima, Michele Arzano   +2 more
wiley   +1 more source

All-multiplicity amplitudes in impulsive PP-waves from the worldline formalism

Journal of High Energy Physics
We use the worldline formalism to derive Bern-Kosower type Master Formulae for the tree-level scattering of a charged particle and an arbitrary number of photons on impulsive PP-waves, where the coupling of the PP-wave to matter is treated fully non ...
Patrick Copinger, James P. Edwards, Anton Ilderton, Karthik Rajeev   +3 more
doaj   +1 more source

Large-order behavior and nonperturbative effects [PDF]

Nuclear Physics B, 1995
Abstract We consider the energy-dependence of the large-order behavior of forward scattering amplitudes in theories having explicit mass parameters and instanton solutions. We show that in weak coupling theories the exponential part of the Espinosa-Ringwald type cross section can be determined by taking the minimum element of the perturbative series,
openaire   +2 more sources

Numerical and analytical inspection of magnetic field effects in the radical pair mechanism by a simplified rate equation model

Bioelectromagnetics, Volume 45, Issue 8, Page 399-405, December 2024.
Abstract The radical pair mechanism is by now the most prominent candidate for a biologically relevant quantum effect of magnetic fields. Recently, N. Ikeya and J. R. Woodward demonstrated a magnetic field effect for sub‐extremely low frequency (ELF) fields in the mT range by investigating the autofluorescence spectrum of flavin adenine dinucleotide in
Andreas Deser, Jens Kuhne, Heinrich A. M. Leymann   +2 more
wiley   +1 more source

Tubings, chord diagrams, and Dyson–Schwinger equations

Journal of the London Mathematical Society, Volume 110, Issue 5, November 2024.
Abstract We give series solutions to single insertion place propagator‐type systems of Dyson–Schwinger equations using binary tubings of rooted trees. These solutions are combinatorially transparent in the sense that each tubing has a straightforward contribution.
Paul‐Hermann Balduf, Amelia Cantwell, Kurusch Ebrahimi‐Fard, Lukas Nabergall, Nicholas Olson‐Harris, Karen Yeats   +5 more
wiley   +1 more source

Complex eigenvalue instantons and the Fredholm determinant expansion in the Gross-Witten-Wadia model

Journal of High Energy Physics
We study the leading nonperturbative corrections to the strong-coupling (ungapped) phase of the Gross-Witten-Wadia (GWW) integral over unitary matrices, to one-loop order.
Dan Stefan Eniceicu, Raghu Mahajan, Chitraang Murdia   +2 more
doaj   +1 more source

Elliptic genus derivation of 4d holomorphic blocks

Journal of High Energy Physics, 2018
We study elliptic vortices on ℂ × T 2 by considering the 2d quiver gauge theory describing their moduli spaces. The elliptic genus of these moduli spaces is the elliptic version of vortex partition function of the 4d theory. We focus on two examples: the
Matteo Poggi
doaj   +1 more source