<div dir="ltr"><div><span id="gmail-m_6191189673296285573docs-internal-guid-6d59fdf2-7fff-9a15-cecc-67df4510c0fe"><div>Announcement of the next <span class="gmail-il">gravity</span>-<span class="gmail-il">theory</span> <span class="gmail-il">webinar</span>:</div><div><br></div><div><b>Jonas P. Pereira</b> (Nicolaus Copernicus Astronomical Center, Warsaw) <br></div><div>Monday, Feb 8th, h12pm</div><div><br></div><div style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><u>Title</u>: </span><span style="font-family:Roboto,sans-serif;font-weight:700;white-space:pre-wrap">Probing elastic quark phases in hybrid stars</span></div><div style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><br></span></div><div style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><u>Abstract</u>: </span><span style="white-space:pre-wrap">The internal composition of neutron stars is currently unknown. Due to the possibility of phase transitions in quantum chromodynamics, stars could be hybrid and have quark cores. In this talk I will discuss some imprints of elastic quark phases on hybrid stars and possible ways to probe them. In particular, I'll show that in the simplest case of unstrained backgrounds a quark elasticity already increases the dynamical stability window of hybrid stars in the sense that the onset of instabilities happen at larger central densities than the ones for maximum masses. As a result, in the conservative case where the shear modulus of a crystalline quark phase in QCD is taken at face value, the maximum relative radius dispersion (on top of the perfect-fluid predictions) would be of just a few percent (less than ~5%) for stable stars exclusively due to the elasticity of the quark phase. However, in the more agnostic approach where the estimates for the quark shear modulus only suggest its possible order of magnitude (due to the many approximations taken in its calculation), the relative radius dispersion uniquely due to a quark phase elasticity could be much larger. Finally, I'll discuss what this could mean when it comes to the probe of a quark phase elasticity with current and future electromagnetic missions such as NICER, eXTP and ATHENA.</span></div></span><div><br></div><div>Zoom link: <a href="https://uniroma1.zoom.us/j/81283707469?pwd=SzkyMk5jRm0xcEN3WE5MYVh1RVFtQT09" target="_blank">https://uniroma1.zoom.us/j/81283707469?pwd=SzkyMk5jRm0xcEN3WE5MYVh1RVFtQT09</a></div>ID meeting: 812 8370 7469<br>Passcode: 915450<br></div><div><br></div>Cheers,<div>Paolo<br><br>-- <br>Paolo Pani <br>Associate Professor<br>ERC StG Fellow, DarkGRA project<br>Junior Fellow, Scuola Superiore di Studi Avanzati Sapienza<br><br>Physics Department (Marconi Building), 3rd floor, room 334<br>Sapienza University of Rome<br>Piazzale Aldo Moro 5 - 00185 Rome (Italy) <br>+39 06 4991 4472 (int 24472)</div></div>
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