Scientists have argued about the origins of Mercury's smooth plains and the source of its magnetic field for more than 30 years. Now, data from the January 2008 flyby of the planet by MESSENGER spacecraft have shown that volcanoes were

Mercury's magnetic field is "alive." Volcanic vents ring the planet's giant Caloris basin while the planet itself is surrounded by a plasma nebula of unexpected complexity.

Stochastic microlensing is a central tool in probing dark matter on galacticscales. From first principles, we develop certain building blocks for amathematical theory of stochastic microlensing. Beginning with the random timedelay function and associated lensing map, we determine exact expressions

We present a reformulation of loop quantum gravity with a cosmologicalconstant and no matter as a Fermi-liquid theory. When the topological sector isdeformed and large gauge symmetry is broken, we show that the Chern-Simonsstate reduces to Jacobson's degenerate sector describing

Supermassive black holes ejected from galaxy nuclei by gravitational waverecoil will carry a retinue of bound stars, even in the absence of an accretiondisk. We discuss the observable signatures related to these stars, with anemphasis on electromagnetic flares from stars

In this paper, we present a successful implementation of a subtraction-noiseprojection method into a simple, simulated data analysis pipeline of agravitational-wave search. We investigate the problem to reveal a weakstochastic background signal which is covered by a strong foreground ofcompact-binary

We analyse strong lensing in the Einstein-Straus solution with positivecosmological constant. For concreteness we compare the theory to the lightdeflection of the lensed quasar SDSS J1004+4112.

It is well known that general relativity does not admit gravitational geonsthat are stationary, asymptotically flat, singularity free and topologicallytrivial. However, it is likely that general relativity will receive correctionsat large curvatures and the modified field equations may admit solutionscorresponding

We consider the one-loop effective action due to gravitons in a FLRWbackground with constant epsilon=-(dH/dt)/H^2. By expanding around epsilon=0(corresponding to an expansion around de Sitter space), we can study how thedeviation from de Sitter space effects the quantum corrected Friedmannequations.

We consider the quantum Friedmann equations which include one-loop vacuumfluctuations due to gravitons and scalar field matter in a FLRW background withconstant epsilon=-(dH/dt)/H^2. The resulting expression shows a secular growthif epsilon=n/(1+n) or epsilon=(n+1)/n, with n positive integer and epsilon !={0,1}.

We study cosmic Nielsen-Olesen strings in space-times with a positivecosmological constant. For the free cosmic string in a cylindrically symmetricspace-time, we calculate the contribution of the cosmological constant to theangle deficit, and to the bending of null geodesics. For a

We consider three versions of the Dirac equation in a curved spacetime: thestandard (Dirac-Fock-Weyl or DFW) equation, and two alternative versions, bothof which are based on the recently proposed tensor representation of the Diracfield (TRD). These three equations differ in

By studying the Hawking radiation of the most general static sphericallysymmetric black hole arising from scalar and Dirac particles tunnelling, wefind the Hawking temperature is invariant in the general coordinaterepresentation (\ref{arbitrary1}), which satisfies two conditions: a) itsradial coordinate transformation is

An analytic solution for the accretion of ultra-hard perfect fluid onto amoving Kerr-Newman black hole is found. This solution is a generalization ofthe previously known solution by Petrich, Shapiro and Teukolsky for a Kerrblack hole. Our solution is not applicable

In this paper I examine cosmological models that contain a stochasticbackground of nonlinear electromagnetic radiation. I show that for Born-Infeldelectrodynamics the equation of state parameter, $w=P/\rho$, remains close to1/3 throughout the evolution of the universe if $E^2=B^2$ in the late

We use the conservation law of the stress-energy and spin tensors to studythe motion of massive zero-size objects in Riemann-Cartan geometry. Theresultant world line equations turn out to exhibit a novel spin-curvaturecoupling. In particular, the spin of the Dirac particle