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<div style="font-family: Tahoma, Geneva, sans-serif; color: rgb(0, 0, 0);"><span style="font-size: 14pt;"><b><i>"Dispersive shock waves in the discrete nonlinear Schrödinger equation"</i></b></span></div>
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<span style="font-size: 12pt;"><br>
</span><span style="font-size: 14pt;"><b>Sathya Chandramouli<br>
</b></span><span style="font-size: 12pt;">University of Massachusetts Amherst </span></div>
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Please feel free to forward/share this invitation with other groups/disciplines that might be interested in this talk/topic. All are welcome to attend. </div>
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NOTE: In-person attendance is requested in our 499 Dirac Science Library (DSL) Seminar Room. Zoom access is intended for external (non-departmental) participants only. </div>
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<b>https://fsu.zoom.us/j/94273595552 </b></div>
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Meeting # <b>942 7359 5552 </b></div>
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🎦 Colloquium recordings will be made available here, <a href="https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.sc.fsu.edu%2Fcolloquium&data=05%7C02%7Csc-seminar-announce%40lists.fsu.edu%7Ce06b425f76bc4348fcb508de5c5f2ea5%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C639049761030105078%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=fepOSauRRYqhh4VvswbVq0EqqD%2ByfI%2BWondZR9lehLs%3D&reserved=0" originalsrc="https://www.sc.fsu.edu/colloquium">
https://www.sc.fsu.edu/colloquium</a> </div>
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<b>Wednesday, Jan 28, 2026, Schedule: </b></div>
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* 3:00 to 3:30 PM Eastern Time (US and Canada) </div>
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☕ Nespresso & Teatime - 417 DSL Commons </div>
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<b>* 3:30 to 4:30 PM Eastern Time (US and Canada) </b></div>
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<b>🕟 Colloquium - 499 DSL Seminar Room </b></div>
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<b>Abstract: </b></div>
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In conservative media, the dispersive regularization of gradient catastrophe gives rise to dispersive shock waves (DSWs). Unlike classical viscous shocks, a DSW is a highly oscillatory nonlinear wavetrain whose leading edge propagates faster than the long-wave
speed, while the entire structure expands over time. A powerful framework for describing DSWs is Whitham modulation theory (WMT), a nonlinear WKB-type approach that captures the slow evolution of wave parameters such as amplitude, wavelength, and frequency.</div>
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In this talk, we study DSWs in the one-dimensional discrete, defocusing nonlinear Schrödinger equation (DNLS), with a particular focus on strongly discrete regimes approaching the anti-continuum limit (ACL), as well as intermediate regimes bridging the ACL
and the continuum limit. Using WMT in combination with asymptotic reductions, we analyze the long-time evolution of step initial data and elucidate how lattice-induced dispersion alters shock structure. Our analysis reveals a sharp discretization threshold
beyond which continuum DSW dynamics are recovered, as well as a rich variety of intermediate shock morphologies unique to the discrete setting. Finally, we apply these results to shock wave formation in ultracold atomic gases confined in optical lattices,
within the framework of the tight-binding approximation.</div>
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Additional colloquium details can be found here, </div>
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<a href="https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.sc.fsu.edu%2Fnews-and-events%2Fcolloquium%2F1903-colloquium-with-sathya-chandramouli-2026-01-28&data=05%7C02%7Csc-seminar-announce%40lists.fsu.edu%7Ce06b425f76bc4348fcb508de5c5f2ea5%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C639049761030139989%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=gBOXTfF9XJzD%2Buwjm978da505OTxecJLED9Ti3N1OoM%3D&reserved=0" originalsrc="https://www.sc.fsu.edu/news-and-events/colloquium/1903-colloquium-with-sathya-chandramouli-2026-01-28">https://www.sc.fsu.edu/news-and-events/colloquium/1903-colloquium-with-sathya-chandramouli-2026-01-28</a></div>
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