Search results for "Theoretical Physics"

Modeling in cardiovascular biomechanics

2010

In this review, we briefly summarize some of Professor K.R. Rajagopal's contributions to the field of cardiovascular mechanics and highlight some applications that have employed his theories and have expanded the ability to model the complex behaviors that characterize biological tissues. His contributions, spawning directly from the classical nonlinear theories of mechanics, have had general impact in diverse fields of engineering. Within biomechanics per se, Rajagopal's efforts have provided state-of-the-art modeling tools not only to characterize tissues, such as blood vessels, cerebral aneurysms, or blood, but also to characterize their evolution, i.e. vessel growth and remodeling or bl…

Analytic structure ofϕ4theory using light-by-light sum rules

2013

Abstract We apply a sum rule for the forward light-by-light scattering process within the context of the ϕ 4 quantum field theory. As a consequence of the sum rule a stringent causality criterion is presented and the resulting constraints are studied within a particular resummation of graphs. Such resummation is demonstrated to be consistent with the sum rule to all orders of perturbation theory. We furthermore show the appearance of particular non-perturbative solutions within such approximation to be a necessary requirement of the sum rule. For a range of values of the coupling constant, these solutions manifest themselves as a physical bound state and a K-matrix pole. For another domain …

Generalized Many-Body Expanded Full Configuration Interaction Theory

2019

Facilitated by a rigorous partitioning of a molecular system's orbital basis into two fundamental subspaces - a reference and an expansion space, both with orbitals of unspecified occupancy - we generalize our recently introduced many-body expanded full configuration interaction (MBE-FCI) method to allow for electron-rich model and molecular systems dominated by both weak and strong correlation to be addressed. By employing minimal or even empty reference spaces, we show through calculations on the one-dimensional Hubbard model with up to 46 lattice sites, the chromium dimer, and the benzene molecule how near-exact results may be obtained in a entirely unbiased manner for chemical and physi…

Anomalies from the phenomenological and geometrical points of view

2008

Chiral anomalies are reviewed according to three different points of view: the usual approach together with some phenomenological implications, the algebraic approach, and, in the end and more detailed, the geometric approach. In particular, the topological approach of the Atiyah-Singer is extended in a way which allows the treatment of all chiral anomalies within the geometric (equivariant) point of view.

Implementation of local chiral interactions in the hyperspherical harmonics formalism

2021

With the goal of using chiral interactions at various orders to explore properties of the few-body nuclear systems, we write the recently developed local chiral interactions as spherical irreducible tensors and implement them in the hyperspherical harmonics expansion method. We devote particular attention to three-body forces at next-to-next-to leading order, which play an important role in reproducing experimental data. We check our implementation by benchmarking the ground-state properties of $^3$H, $^3$He and $^4$He against the available Monte Carlo calculations. We then confirm their order-by-order truncation error estimates and further investigate uncertainties in the charge radii obta…

On divisible designs and twisted field planes

1999

An example of cancellation of infinities in the star-quantization of fields

1993

Within the *-quantization framework, it is shown how to remove some of the divergences occurring in theλo 2 4 -theory by introducing aλ-dependent *-product cohomologically equivalent to the normal *-product.

New dimension indices for the characterization of the solvent-accessible surface

2001

Pseudo-bosons and Riesz Bi-coherent States

2016

After a brief review on D-pseudo-bosons we introduce what we call Riesz bi-coherent states, which are pairs of states sharing with ordinary coherent states most of their features. In particular, they produce a resolution of the identity and they are eigenstates of two different annihilation operators which obey pseudo-bosonic commutation rules.

Search for New Physics with Atoms and Molecules

2017

This article reviews recent developments in tests of fundamental physics using atoms and molecules, including the subjects of parity violation, searches for permanent electric dipole moments, tests of the CPT theorem and Lorentz symmetry, searches for spatiotemporal variation of fundamental constants, tests of quantum electrodynamics, tests of general relativity and the equivalence principle, searches for dark matter, dark energy and extra forces, and tests of the spin-statistics theorem. Key results are presented in the context of potential new physics and in the broader context of similar investigations in other fields. Ongoing and future experiments of the next decade are discussed.