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<p>Theory Center Seminar<br>
Monday, Sept. 18, 2017<br>
1:00 p.m. (coffee at 12:45 p.m.)<br>
CEBAF Center, Room L102<br>
<br>
Thomas Cohen<br>
University of Maryland<br>
<br>
<b><span>The </span></b><b><span
class="m_8967686140100482911m_8286460625798280417gmail-il">Sign</span></b><b><span>
</span></b><b><span
class="m_8967686140100482911m_8286460625798280417gmail-il">Problem</span></b><b><span> and
the Theta Term</span></b> </p>
<div>This talk explores the <span
class="m_8967686140100482911m_8286460625798280417gmail-il">sign</span> <span
class="m_8967686140100482911m_8286460625798280417gmail-il">problem</span> in
lattice calculations. For concreteness, the talk focuses on the
energy <br>
density as a function of theta for gauge theories when a
topological CP violating term is included. The emphasis<br>
is on subtleties associated with the the infinite volume limit. A
key question addressed is the extent to which<br>
information about the infinite volume limit of the energy density
as a function of topological charge density is <br>
sufficient to fully reconstruct the infinite volume energy density
as a function of theta. Implications for more <br>
general problems in QCD where sign problems arise will be
discussed.</div>
<div class="gmail_extra"><br>
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