Cosmic acceleration could be an effect of a ""dark energy"" fluid pervading the Universe. It could also be an indication that general relativity is not the correct theory of gravity at cosmological length scales. Unfortunately, observations of the...
Casimir effect. Zero-point field. Electric conductivity. Quantum electrodynamics.
The Casimir force arises from an alteration of boundary condition in vacuum and is often regarded as a manifestation of quantum zero point energy. Considerable progress has been made in the last decade with an impressive achievement of experimental...
We begin with a result on the refocussing of null geodesics in space-times. We show that all oriented refocussing 2-dimensional Lorentz manifolds are also strongly refocussing. We also introduce a theory of virtual Legendrian knots. We show that...
From deciding what to eat first or what stock to invest in, the order in which we prefer to experience events and the amount of risk we are willing to undertake are factors that influence our choices. However, the mechanisms underlying order and...
Breast -- Cancer -- Tomography. ; Breast -- Cancer -- Imaging. ; Microwave imaging in medicine. ; Breast -- Electric properties. ; Breast Neoplasms -- diagnosis. ; Diagnostic Imaging -- methods.
While Cherenkov emission was discovered more than eighty years ago, the potential applications of imaging this during radiation therapy have just recently been explored. With approximately half of all cancer patients being treated by radiation at...
The accelerated expansion of space in the Universe has been known for two decades. However, finding a plausible theory that describes this expansion is more difficult: Taking general relativity for granted requires us to stipulate the existence of...
The new APM South Equatorial Strip Catalog $({-}17\sp\circ.5<\delta<2\sp\circ.5)$ is used to select a sample of early-type galaxies in three directions: (1) 15h10-16h10; (2) 20h30-21h50; (3) 00h10-01h30. The distances and peculiar motions of...
Magnetic fields at all scales are prevalent in our universe. However, current cosmological models predict that initially the universe was bereft of large-scale fields. Standard magnetohydrodynamics (MHD) does not permit magnetogenesis; in the MHD...
Space and time in language. ; Space perception. ; Figure-ground perception. ; Psycholinguistics.
Across languages, there exists a relatively small number of spatial prepositions. These terms are used to express the infinite number of possible spatial locations of an unlimited number of different entities in the environment. Previous research...
Relativity (Physics). ; Anisotropy -- Mathematical models. ; Einstein field equations. ; Newtonian fluids. ; Astrophysics.
We study the effects of anisotropic pressure on the properties of spherically symmetric, gravitationally bound spheres. We consider the full general-relativistic and Newtonian treatment of this problem and obtain exact solutions for various forms...
In this thesis we review the methods for computation of cosmological correlations in the early universe known as the in-in formalism which are then applied to the problem of magnetogenesis from inflation. For this computation, a power-law single...
Successfully navigating our social world requires the ability to understand the facial expressions of others. Indeed, facial expressions provide information about the emotions and intentions of others. While some expressions provide clear...
For a long-lived metastable system, the decay of the survival probability is typically exponential. However, deviations are known to exist at short times (the quantum Zeno effect) and at long times (algebraic tails in classical hydrodynamic...
In this work we investigate the quantum dynamics of three different configurations of nonlinear cavity systems. We begin by carrying out a quantum analysis of a dc superconducting quantum interference device (SQUID) mechanical displacement detector...
Manifolds (Mathematics) Geodesics (Mathematics) Space and time.
We investigate weak and strong refocusing of light rays in a space-time and related concepts. A strongly causal space-time ( X^ n +1 , g ) is emphstrongly refocusing at x ∈ X if there is a point y ≠ x such that all null-geodesics through y pass...
Strong evidence exists showing that stellar evolution models are unable to accurately predict the fundamental properties of low-mass stars. Observations of low-mass stars in detached eclipsing binaries (DEBs) indicate that stellar models...