Ical
https://bhi.fas.harvard.edu/calendar?type=month&month=upcoming
enBHI Colloquium
https://bhi.fas.harvard.edu/event/bhi-colloquium-60
<div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><span class="field-item even"><p style="text-align:center">
<strong>Martin LeSourd (Mathematics)</strong> - BHI
</p>
<p style="text-align:center">
<span><iframe class="youtube-video" src="https://www.youtube.com/embed/UuRNBd1KuxA?feature=oembed" width="480" height="270" scrolling="no" title="BHI Colloquium (September 27, 2021) - Martin Lesourd" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="1"></iframe></span>
</p>
<p>
<strong>Title: The topology of space outside black holes</strong>
</p>
<p>
Abstract: It has long been known (mid 90s) that assuming certain topological properties about a spacetime’s future conformal boundary, along with various other reasonable assumptions, forces the region outside a black hole to be topologically trivial. This result and the ones that have come after are known as “topological censorship”. In light of those theorems, we asked ourselves the following: i) what happens if we introduce a positive cosmological constant term (as observations suggest), and ii) can we get rid of assumptions about the topology of the future conformal boundary? I shall describe the answers we found to those questions. The work is joint with E.Ling.
</p>
<p>
Bio: Martin Lesourd completed his undergraduate and graduate studies in Mathematics, Physics and Philosophy at (Trinity) Cambridge University and (Linacre) Oxford University. He is a mathematician whose research lies in two disciplines: general relativity and geometric analysis. Broadly speaking, his aim is to better understand a space - this could be a spacetime (which contains a black hole for instance) or a Riemannian Manifold - by studying Partial Differential Equations that can be associated to that space. With regards to general relativity, he studies both the Einstein equations and the Constraint equations, and most recently has been trying to describe the formation of black holes from a purely mathematical standpoint.
</p>
<p>
</p>
<ul></ul></span></div>Mon, 27 Sep 2021 11:00:00 -0400Fabio1408505 at https://bhi.fas.harvard.eduBHI Colloquium
https://bhi.fas.harvard.edu/event/bhi-colloquium-61
<div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><span class="field-item even"><p style="text-align:center">
<strong>Lydia Patton (Philosophy)</strong> - BHI
</p>
<p>
<strong>Title: Epistemic Analysis of the EOB and EMRI Method</strong>
</p>
<p>
Abstract: The Effective One-Body (EOB) formalism and the Extreme Mass Ratio Inspiral (EMRI) methods involve the following general steps (Hughes 2000, Cornish 2008, Buonanno and Damour 1999):
</p>
<ul><li>
Modeling binary systems so that one body stands in for the dynamics of the entire system.
</li>
<li>
Modeling the system using one-body dynamics.
</li>
<li>
Finding a way to represent the 'extra' body: perturbation (EMRI) or resummation (EOB).
</li>
</ul><p>
This talk will analyze two related means of epistemic analysis of these methods. First, the expansion of tractable solutions using creative modeling, within the framework of what Bokulich (2011) calls structural model explanations. Second, the use of surrogative reasoning within structural model explanations. The epistemic analysis will be used to evaluate challenges for future extensions of (or revisions to) EMRI and EOB methods.
</p>
<p>
Bio: Lydia Patton is a philosopher of science and a historian of the philosophy of science. Much of her recent work and work in progress centers on philosophical analysis of science and the history of science: especially on the development of experimental and formal methods, hypotheses, frameworks, and scientific communities. Her work focuses on finding links between that development and the process of theory building and testing. Recent work focuses on the development of gravitational wave astronomy, especially the <a href="https://www.ligo.caltech.edu/" target="_blank">LIGO project</a>. Patton has written many articles, details of which can be found on her <a href="https://lydiapatton.weebly.com/" target="_blank">personal website</a> and on the website <a href="https://philpeople.org/profiles/lydia-patton" target="_blank">philpapers</a>.
</p>
<p>
</p>
</span></div>Mon, 04 Oct 2021 11:00:00 -0400Fabio1408506 at https://bhi.fas.harvard.eduBHI Colloquium
https://bhi.fas.harvard.edu/event/bhi-colloquium-63
<div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><span class="field-item even"><p>
<strong>"</strong>TBD" - <strong>Christina Eilers (Astronomy)</strong> - MIT
</p>
</span></div>Mon, 18 Oct 2021 11:00:00 -0400Fabio1408508 at https://bhi.fas.harvard.eduBHI Colloquium
https://bhi.fas.harvard.edu/event/bhi-colloquium-62
<div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><span class="field-item even"><strong>"</strong>TBD" - <strong>Martin LeSourd (Mathematics)</strong> - BHI</span></div>Mon, 25 Oct 2021 11:00:00 -0400Fabio1409668 at https://bhi.fas.harvard.eduBHI Colloquium
https://bhi.fas.harvard.edu/event/bhi-colloquium-66
<div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><span class="field-item even"><strong>"</strong>TBD" - <strong>Ken Ng (Astronomy)</strong> - MIT</span></div>Mon, 01 Nov 2021 11:00:00 -0400Fabio1415591 at https://bhi.fas.harvard.eduBHI Colloquium
https://bhi.fas.harvard.edu/event/bhi-colloquium-65
<div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><span class="field-item even"><p style="text-align:center">
<strong>Stefan Czimek</strong><strong> (Mathematics) </strong>- Brown University
</p>
<p>
<strong>Title: The characteristic gluing problem of general relativity</strong>
</p>
<p>
Abstract: <span style="margin:0px"><span style="color:#201f1e"><span style="font-style:normal"><span><span><span style="font-weight:400"><span><span><span style="text-transform:none"><span><span><span><span><span><span><span>In this talk we introduce and solve the characteristic gluing problem for the Einstein vacuum equations. We show that obstructions to characteristic gluing come from an infinite-dimensional space of conservation laws along null hypersurfaces for the linearized equations at Minkowski. We prove that this space splits into an infinite-dimensional space of gauge-dependent charges and a 10-dimensional space of gauge-invariant charges. We identify the 10 gauge-invariant charges to be related to the energy, linear momentum, angular momentum and center-of-mass of the spacetime. Based on this identification, we explain how to characteristically glue a given spacetime to a suitably chosen Kerr spacetime. As corollary we get an alternative proof of the Corvino-Schoen spacelike gluing to Kerr. </span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><span style="margin:0px"><span style="color:#201f1e"><span style="font-style:normal"><span><span><span style="font-weight:400"><span><span><span style="text-transform:none"><span><span><span><span><span><span><span>Moreover, we apply our characteristic gluing method to localise characteristic initial data along null hypersurfaces. In particular, this yields a new proof of the Carlotto-Schoen spacelike localization where our method yields no loss of decay, thus resolving an open problem. We also outline further applications. This is joint work with S. Aretakis (Toronto) and I. Rodnianski (Princeton).</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
</p>
<p>
<span style="margin:0px"><span style="color:#201f1e"><span style="font-style:normal"><span><span><span style="font-weight:400"><span><span><span style="text-transform:none"><span><span><span><span><span><span><span>Bio: Stefan Czimek is </span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>a mathematician working in general relativity, and currently at the <a href="https://icerm.brown.edu/">ICERM</a> @ <a href="https://www.brown.edu/">Brown University</a> as an <em>Institute Postdoctoral Fellow</em>. In his research he uses tools from analysis, PDE theory and differential geometry to study fundamental questions of general relativity.
</p>
</span></div>Mon, 22 Nov 2021 11:00:00 -0500Fabio1415519 at https://bhi.fas.harvard.eduBHI Colloquium
https://bhi.fas.harvard.edu/event/bhi-colloquium-64
<div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><span class="field-item even"><strong>"</strong>TBD" - <strong>Aghil Alaee (Physics)</strong> - Clark University</span></div>Mon, 06 Dec 2021 11:00:00 -0500Fabio1409722 at https://bhi.fas.harvard.edu