## Selected Presentations & Appearances

This talk, which is really two 30 minutes talks back-to-back, may be viewed at:

http://www.birs.ca/events/2016/5-day-workshops/16w5054/videos/watch/201607181602-Bray.html

Differential geometry seminar at Stanford University

The recent detection of gravitational waves is another spectacular confirmation that the universe is fundamentally geometric, at least on cosmological scales. This raises a natural question: Could dark matter, which makes up most of the mass of galaxies, be fundamentally geometric as well? We'll present a geometric model of dark matter called wave dark matter, also known as scalar field dark matter and Bose-Einstein condensate dark matter, which fits observations about dark matter very well. Using geometric PDE, we'll show how wave dark matter predicts spiral patterns in galaxies, and compare computer simulations with photos of actual galaxies.

From Pythagoras to Einstein: The Geometry of Space and Time

6:00 p.m. - 7:00 p.m.

Earth Sciences Museum

EIT 1015

Pythagoras was an ancient Greek who was not only a mathematician, but also a religious cult

leader. He and his followers believed that the key to unlocking the mysteries of the universe was

hidden somewhere inside mathematics and geometry. Crazy, right? Well, it turns out he was

right. Thousands of years later, based on the work of the mathematicians Gauss and Riemann,

Einstein discovered a hidden geometry of the universe. Starting with the Rule of Pythagoras for

right triangles, we’ll survey the ideas which led to Einstein’s historic discovery and how it relates

to black holes, the Big Bang, and the unification of space and time.

7:15 p.m. - 8:00 p.m.

Earth Sciences Museum

EIT 1015

Is time travel possible? Are there other universes? Does life exist on other planets? What is Einstein’s Theory of Relativity? How do you count in base 7, and why would anyone do this? These are some of the serious questions which relate to the speaker’s science fiction book “Trevor the Time Traveler” about Trevor and his sister Farrah. We’ll also hand out free “Golden Thank Yous” - the official currency of the Milky Way galaxy - which is based on the Fibonacci sequence.

Note: You do not need to have read “Trevor the Time Traveler” to enjoy this lecture. Copies of the

book may be purchased at the event. The author will sign copies of the book.

Target audience: Ages 8 - 18 and up

https://uwaterloo.ca/math/sites/ca.math/files/uploads/files/bray_public_lectures_march9.pdf

URL: http://www.math.duke.edu/~bray/Presentations/WingLecture3.pdf

URL: http://www.math.duke.edu/~bray/Presentations/WingLecture2.pdf

http://www.math.duke.edu/~bray/Presentations/WingLecture1.pdf

http://www.math.rochester.edu/about/colloquia/Wing/Bray.html

Invited Lectures ; H. L. Bray ; http://www.math.rochester.edu/about/colloquia/Wing/Bray.html

Invited Lectures ; H. L. Bray ; http://www.math.duke.edu/~bray/Presentations/WingLecture3.pdf

Invited Lectures ; H. L. Bray ; http://www.math.duke.edu/~bray/Presentations/WingLecture1.pdf

Invited Lectures ; H. L. Bray ; http://www.math.duke.edu/~bray/Presentations/WingLecture2.pdf

Invited Lectures ; H. L. Bray

Invited Lectures ; Hubert L. Bray ; http://www.huffingtonpost.com/frank-morgan/dark-matter-and-worst-packings_b_3336772.html ; More than 95% of the present day curvature of the universe is not a result of regular baryonic matter represented by the periodic table of elements. About 73% is well described by a geometrically natural cosmological constant, also referred to as dark energy, which results in a very small amount of curvature uniformly spread throughout the universe. We will explore the possibility that the remaining 23%, commonly referred to as dark mater, could also be explained very naturally from a geometric point of view. We propose geometric axioms which result in the Einstein-Klein-Gordon equations and model dark matter with the resulting scalar field. We will present simulations and models of the resulting ``wave dark matter'' theory (aka scalar field dark matter and boson stars) in dark matter dominated systems including spiral galaxies, elliptical galaxies, and dwarf spheroidal galaxies. We will compare these predictions to the observed data and photos of actual galaxies.

Invited Lectures ; Hubert L. Bray ; http://www.math.duke.edu/~bray/Presentations/2013_SCGAS.pdf ; More than 95% of the present day curvature of the universe is not a result of regular baryonic matter represented by the periodic table of elements. About 73% is well described by a geometrically natural cosmological constant, also referred to as dark energy, which results in a very small amount of curvature uniformly spread throughout the universe. We will explore the possibility that the remaining 23%, commonly referred to as dark mater, could also be explained very naturally from a geometric point of view. We propose geometric axioms which result in the Einstein-Klein-Gordon equations and model dark matter with the resulting scalar field. We will present simulations and models of the resulting ``wave dark matter'' theory (aka scalar field dark matter and boson stars) in dark matter dominated systems including spiral galaxies, elliptical galaxies, and dwarf spheroidal galaxies. We will compare these predictions to the observed data and photos of actual galaxies.

Invited Lectures ; Hubert L. Bray ; http://160.36.161.128/UTK/Viewer/?peid=48d07f6bdea64db4a7641cfeb945f9eb

Invited Lectures ; H. L. Bray ; http://www.math.duke.edu/~bray/darkmatter/GeomFest.pdf

Invited Lectures ; Hubert L. Bray ; https://www.math.duke.edu/video/video.html?_vidId=fdbf2d6973c23cdb8ad21172b812b047

Invited Lectures ; Hubert L. Bray ; https://www.math.duke.edu/video/video.html?_vidId=45577794c6cf556717ac67d4fd82a46b ; 45577794c6cf556717ac67d4fd82a46b

Invited Lectures ; Hubert Bray ; https://www.math.duke.edu/video/video.html?_vidId=a6288ef0bf808055ea9bce3271964d31 ; This was a general audience lecture hosted by the University of Tennessee attended by a wide range of people, including many high school and college students.

112 minutes total - Part I (66 minutes): Bray describes the astronomical evidence for dark matter in galaxies. Part II (21 minutes, 66 minutes in): Badin describes searches for dark matter particles. Part III (25 minutes, 87 minutes in): Bray describes his work on a general relativity approach to dark matter described by a scalar field satisfying the Klein-Gordon equation as a possible explanation for spiral patterns in galaxies.

URL: https://www4.math.duke.edu/video/video.html?_vidId=07d6c44132bdd3a822b1707407129e82

Invited Lectures ; Hubert Bray ; https://www.math.duke.edu/video/video.html?_vidId=830435f42d80c6b48d621f0f9187d43a

https://www4.math.duke.edu/video/video.html?_vidId=3837c0c6d856afbc6661861d653bc04b

https://www.math.msu.edu/Seminar/Stream/RTG/2005/play_bray_lecture_512.html

http://www-old.newton.ac.uk/webseminars/pg+ws/2005/gmr/0830/bray/

http://fanfreluche.math.univ-tours.fr/

http://fanfreluche.math.univ-tours.fr/

https://www4.math.duke.edu/video/video.html?_vidId=804d7a0d6282eca24391d7de07583117

https://www4.math.duke.edu/video/video.html?_vidId=74434745483fe42abe8667629e336d4f

http://online.itp.ucsb.edu/online/gravity_c99/bray/

## Outreach & Engaged Scholarship

## Service to the Profession

Conferences organized

Conferences Organized

Conferences Organized

Conferences Organized ; This conference was organized by an international committee of astrophysicists to advertise the known astronomical data about dark matter in galaxies. They put together a base presentation which they then sent to 150 or so universities to be presented the same week. I was asked to present at Duke because of my recent paper in this area, and then I asked Andriy Badin from physics to help present. I am sure most of the other presenters were astrophysicists and astronomers, but the exercise was a great one for me to master the material in time for the talk. Andriy and I also added our own material to the presentation, which was about an hour and forty-five minutes.

Conferences organized

Conferences Organized

Conferences Organized

Conferences Organized ; This conference was organized by an international committee of astrophysicists to advertise the known astronomical data about dark matter in galaxies. They put together a base presentation which they then sent to 150 or so universities to be presented the same week. I was asked to present at Duke because of my recent paper in this area, and then I asked Andriy Badin from physics to help present. I am sure most of the other presenters were astrophysicists and astronomers, but the exercise was a great one for me to master the material in time for the talk. Andriy and I also added our own material to the presentation, which was about an hour and forty-five minutes.

Conferences Organized

Workshop organized