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<p class="MsoNormal">Dear all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In case you missed it in Ella’s message yesterday, Professor George Efstathiou, one of the top cosmologists in the country and the world, is visiting us today and giving a seminar here in CAPT. See details below. I think it will be a very
interesting seminar, so I recommend you attend if you can. Joining online is also possible.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Best wishes,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Alfonso<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="elementtoproof" style="background:white"><b><span style="font-size:16.0pt;color:black">Tuesday 24<sup>th</sup> February at 1pm, A113 CAPT – Particle Cosmology and Gravity Seminar<o:p></o:p></span></b></p>
<p class="xmsonormal"><span style="font-size:16.0pt;font-family:"Aptos",sans-serif">George Efstathiou (Cambridge)<o:p></o:p></span></p>
<p class="xmsonormal"><span style="font-size:14.0pt;font-family:"Aptos",sans-serif;color:black;mso-fareast-language:EN-US">The Evidence for Dynamical Dark Energy<o:p></o:p></span></p>
<p class="xmsonormal"><span style="font-size:16.0pt;font-family:"Aptos",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="color:black;mso-ligatures:none;mso-fareast-language:EN-GB">The Dark Energy Spectroscopic Instrument (DESI) collaboration has measured baryon acoustic oscillation (BAO) features over a wide range of
redshifts with unprecedented precision. They argue that the data provide evidence for evolving dark energy, quoting 'significance' levels of 2.5-4.5 sigma depending on which additional data (CMB anisotropies and supernovae) are added to the BAO data. The favoured
model of dynamical dark energy is unusual, requiring phantom-like behaviour at high redshift. I will present a different way of looking at the DESI data that provides simple and robust tests of consistency with the LCDM cosmology. I find no evidence for a
deviation from LCDM and my analysis explains the degeneracy direction in the w_0-w_a plane found by the DESI collaborations. I will summarize some recent work on type Ia Supernova (SN) that supports my earlier claims that SN catalogues are not yet accurate
enough to constrain models of dynamical dark energy. </span><span style="color:black;mso-ligatures:none;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="elementtoproof" style="background:white"><b><span style="color:black"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><b><span style="color:black">Link to join:</span></b><span style="color:black"> <a href="https://teams.microsoft.com/l/meetup-join/19%3ameeting_OGM3OTk5NzQtZWEwZS00ZmUyLTk3MGUtZjFhY2M5OTU2MjI1%40thread.v2/0?context=%7b%22Tid%22%3a%2267bda7ee-fd80-41ef-ac91-358418290a1e%22%2c%22Oid%22%3a%22f3250584-4b5f-48fa-a897-08e77f2246b7%22%7d" target="_blank" title="https://teams.microsoft.com/l/meetup-join/19%3ameeting_OGM3OTk5NzQtZWEwZS00ZmUyLTk3MGUtZjFhY2M5OTU2MjI1%40thread.v2/0?context=%7b%22Tid%22%3a%2267bda7ee-fd80-41ef-ac91-358418290a1e%22%2c%22Oid%22%3a%22f3250584-4b5f-48fa-a897-08e77f2246b7%22%7d">https://teams.microsoft.com/l/meetup-join/19%3ameeting_OGM3OTk5NzQtZWEwZS00ZmUyLTk3MGUtZjFhY2M5OTU2MjI1%40thread.v2/0?context=%7b%22Tid%22%3a%2267bda7ee-fd80-41ef-ac91-358418290a1e%22%2c%22Oid%22%3a%22f3250584-4b5f-48fa-a897-08e77f2246b7%22%7d</a></span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="mso-ligatures:none;mso-fareast-language:EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt;font-family:"Arial",sans-serif;color:#009BBD;mso-fareast-language:EN-GB">Alfonso Aragón-Salamanca</span></b><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt;font-family:"Arial",sans-serif;color:#131B57;mso-fareast-language:EN-GB">Professor of Astronomy</span></b><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-GB"> </span><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#131B57;mso-fareast-language:EN-GB">School of Physics and Astronomy<br>
University of Nottingham</span><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#131B57;mso-fareast-language:EN-GB">Room B106b, Centre for Astronomy and Particle Theory</span><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#131B57;mso-fareast-language:EN-GB">University Park</span><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#131B57;mso-fareast-language:EN-GB">Nottingham, NG7 2RD, UK</span><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-GB"> </span><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#131B57;mso-fareast-language:EN-GB">+44 (0) 115 95 16230<b> </b></span><b><span style="font-size:9.0pt;font-family:"Calibri",sans-serif;color:#131B57;mso-fareast-language:EN-GB">| </span></b><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><a href="mailto:alfonso.aragon@nottingham.ac.uk"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:blue">alfonso.aragon@nottingham.ac.uk</span></a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif;color:black;mso-fareast-language:EN-GB">URL:
</span><span style="font-size:12.0pt;mso-fareast-language:EN-GB"><a href="http://nottingham.ac.uk/physics/people/alfonso.aragon"><span style="font-family:"Calibri",sans-serif;color:#0563C1">http://nottingham.ac.uk/physics/people/alfonso.aragon</span></a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-GB">General teaching enquiries
</span><span style="mso-fareast-language:EN-GB"><a href="mailto:physics-teaching@nottingham.ac.uk"><span style="font-family:"Calibri",sans-serif;color:#0563C1">physics-teaching@nottingham.ac.uk</span></a><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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