Theoretical Astronomy

The Evolution of the Laws of Physics

time reborn book cover

Prof. Lee Smolin of the Perimeter Institute in Waterloo, Canada, author and theoretical physcist, will talk about the evolution of laws in our universe.

Conformal gravity: New light on dark matter and dark energy

dark matter Dr. Nesbet will describe (in layman's terms) implications of a theory that differs from standard particle physics and cosmology only by imposing a universal symmetry principle. This theory has been found to explain dark energy and dark galactic halos without invoking dark matter. Subgalactic phenomenology (relevant to our solar system) is retained.

Inflation and the Landscape of String Theory

One of major advances of string theory in recent years was an understanding that vacuum  solutions with potentially viable four-dimensional cosmology come in a plethora of an incredibly large  and rich 'landscape' of string theory vacua. The number of possible vacua and, in turn, types of Universes, may exceed 10 to the power 1000.

Dispersal of Protoplanetary Disks

Protoplanetary disks  originate during star formation and evolve rapidly, to form planetary systems before they disperse in a few million years. Dr. Gorti will describe disk evolution and discuss disk dispersal mechanisms in the context of recent theoretical models. Theory will be compared with observations to summarize our current understanding of how disks evolve and the constraints they set on the time available for planet formation.

Mysteries of the oscillations of gas accreting onto black holes, neutron stars, and white dwarfs

Dr. Wagoner will survey the QPOs (quasi-periodic oscillations) seen in the luminosity fluctuation power spectra of compact objects accreting from a binary companion star. There is little understanding of the different frequency relationships in these systems. Dr. Wagoner will focus on the theory and observations of black holes, and compare the predictions of their spin via diskoseismolgy with those from two other methods.

Are we living in a multiverse? Eternal inflation, bubbles, and cosmic collisions

About a decade ago, we completed an epochal transformation in the understanding of our cosmos, unraveling a broad and deep understanding of how the observable universe has evolved from a hot, dense state 13.7 billion years ago.  Yet a second, even bigger transformation may now be taking place, because this understanding points to a crucial early epoch of "inflationary" cosmic expansion, during which it expanded at a stupendous rate to create the vast amount of space we can observe.  But cosmologists are coming to believe that inflation may do much more: in many versions, inflation goes on f

Do We Need String Theory to Quantize Gravity?

The strong, weak, and electromagnetic interactions all have consistent, relativistic and quantum mechanical descriptions in terms of pointlike particles, but Einstein's theory of gravitation has long resisted a similar treatment, because of severe ultraviolet divergences. String theory solves these problems, but it introduces a new length scale, perhaps 16 orders of magnitude below what can be tested experimentally.

Dark Matter: The Other Universe

A startling discovery in science in the past few decades is most mass in the universe is in "dark matter"- some very clever form of matter capable of speeding up the motion of stars and galaxies while eluding direct detection at the same time. Dr. Ma will summarize the evidence for the existence of dark matter, discuss what it can and cannot be, and describe ongoing research on this mysterious component of the universe.

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