IceCube Particle Astrophysics Symposium 2026

14 Oct 2026, 08:00 → 16 Oct 2026, 15:30 US/Central

Memorial Union

The IPA Symposium brings together the gamma-ray, cosmic-ray, neutrino, and gravitational-wave communities to evaluate the current landscape of multi-messenger astrophysics and discuss the path forward for the next decade.  The timing of the meeting is partly driven by two milestones in the IceCube community: over 15 years of continuous operation of the IceCube Neutrino Observatory, and the upcoming first light from the IceCube Upgrade.

The Symposium will take place in Memorial Union on the University of Wisconsin–Madison campus. We look forward to welcoming you to Madison in October 2026.

Registration and abstract submission are now open.

The abstract submission deadline has been extended to Wednesday, September 30.

Posters should be no larger than 4'x4'.

Join us on the IceCube Slack workspace at #ipa-madison-2026 to ask questions, chat with colleagues, and stay up to date on meeting news and developments.

The organizing committee is excited to announce the following invited speakers:

• Shreya Anand, Stanford University
• Carlos Argüelles-Delgado, Harvard University
• Vedant Basu, University of Utah
• John Beacom, The Ohio State University 
• Brad Benson, University of Chicago
• Delaney Butterfield, University of Wisconsin–Madison
• Paul de Jong, Nikhef: Dutch National Institute for Subatomic Physics and University of Amsterdam
• Viktoriya Dik, Joint Institute for Nuclear Research
• Glennys Farrar, New York University
• Anatoli Fedynitch, Academica Sinica
• Jordan Goodman, University of Maryland
• Elizabeth Hays, NASA Goddard Space Flight Center
• Jamie Holder, University of Delaware
• Walid Idrissi Ibnsalih, University of Naples Federico II
• Marek Kowalski, Humboldt University/DESY
• Pedro Machado, Fermilab
• Mainak Mukhopadhay, University of Chicago
• Kohta Murase, Pennsylvania State University
• Abigail Vieregg, University of Chicago
• Sarah Vigeland, University of Wisconsin-Milwaukee
• Wei Wang, Sun Yat-sen University
• Shigeru Yoshida, Chiba University
• Min Zha, Institute of High Energy Physics, Chinese Academy of Sciences 

Wednesday 14 October

Registration and Check-In

Plenary Session: I

10:30 Coffee Break

Plenary Session: II

1 Space-based Gamma-ray Astronomy

This year marks the 18th launch anniversary of the Fermi Gamma-ray Space Telescope. The Fermi era has opened up access to the GeV gamma-ray sky and enabled science discoveries across a wide range of astronomical phenomena, including white dwarfs, neutron stars, black holes and their energetic activities. With that progress, the field continues to work on big questions about the origins of cosmic explosions, the mechanisms for particle acceleration in astrophysical sources, and the sources of cosmic rays and neutrinos. I will explore several questions in the talk. What have we learned about particle astrophysics through space-based gamma-ray observations? Where has collaborative work between neutrinos and space-based gamma rays made the most impact? What do we hope to do in the future?

Speaker: Elizabeth Hays (NASA Goddard Space Flight Center)

12:30 Lunch (on your own)

Parallell Sessions

15:30 Coffee Break

Parallell Sessions

Special Events: Welcome Reception and Poster Session

Thursday 15 October

Registration and Check-In

Plenary Session: III

2 Physics and Astrophysics with Nanohertz Gravitational Waves

Pulsar timing array experiments around the world have found evidence of nanohertz gravitational waves in the form of a stochastic gravitational wave background. This discovery opens another window on the gravitational wave universe that we can use to study a variety of astrophysical and cosmological sources, as well as perform tests of gravity. Pulsar timing arrays search for gravitational waves by looking for interpulsar correlations in the timing residuals of a collection of millisecond pulsars. In this talk, I will discuss how pulsar timing arrays work, what sources we expect to find emitting nanohertz gravitational waves and what we can learn about them, and how pulsar timing arrays can be used to study fundamental physics.

Speaker: Sarah Vigeland (University of Wisconsin-Milwaukee)

3 The Cosmic Microwave Background: Experimental Status and New Cosmological Constraints

Over the next several years, more sensitive measurements of the polarization anisotropy of the cosmic microwave background (CMB) are poised to lead to substantial improvements in cosmological constraints. On degree angular scales, the amplitude of the B-mode polarization gives a constraint on the energy scale of cosmic Inflation, with measurements in the next several years improving constraints by an order of magnitude. On intermediate angular scales, the CMB polarization anisotropy gives constraints on a range of physics, including the abundance of light relic particle species, the mass of the neutrino, and dark energy. I will describe the experimental landscape pushing these new frontiers of CMB measurements, focusing on the South Pole Telescope (SPT-3G, SPT-3G+) and the BICEP Array (BA) experiment, which combined form the South Pole Observatory (SPO), and the Simons Observatory (SO) in Chile. I will also describe recent and upcoming results, which are forecasted to reduce the allowed Lambda-CDM cosmological parameter space by a factor of 100, with the potential to resolve some of the current cosmic tensions and improve our understanding of the physics of the Universe.

Speaker: Bradford Benson (University of Chicago, Fermilab)

10:30 Coffee Break

Plenary Session: IV

4 Neutrino and multi-messenger astrophysics with IceCube

This talk will cover the analysis of cosmic neutrinos and recent results from the IceCube Neutrino Observatory. We go over measurements of the astrophysical neutrino spectrum and what this reveals about the dynamics of their sources in cosmic ray accelerators. We will also investigate specific neutrino sources, including the Milky Way.

Speaker: Vedant Basu (University of Utah)

12:30 Lunch (on your own)

Plenary Session: V

5 Status of the Baikal-GVD Neutrino Telescope

The Baikal-GVD neutrino telescope is a large-scale underwater detector designed for the study of high-energy cosmic neutrinos and their astrophysical sources. The detector is being continuously expanded in Lake Baikal and is approaching a cubic-kilometer sensitive volume. We present the current status of the telescope, including  real-time data processing and recent astrophysical results obtained with cascade- and track-like events. The prospects for further detector expansion will also be presented.

Speaker: Viktoriya Dik (Joint Institute for Nuclear Research)

6 Status and Recent Results from UHE Neutrino Telescopes

The highest energy astrophysical and cosmogenic neutrinos still await discovery, and allow us to understand the most energetic cosmic accelerators in the universe. I will discuss the status, plans, and highlight recent results from experiments that aim to detect the highest energy neutrinos, focusing on instruments that look for radio emission from in-ice interactions from UHE neutrinos. I will highlight recent results from the Askaryan Radio Array (ARA) experiment, which has been operating at the South Pole for over a decade, discuss the status and plans for the larger Radio Neutrino Observatory in Greenland (RNO-G), and discuss the recent flight of the Payload for Ultrahigh Energy Observations (PUEO), which is a NASA Astrophysics Pioneers Long Duration Balloon Mission, and launched from McMurdo Station in Antarctica on December 20, 2025 and flew for 23 days.

Speaker: Abigail Vieregg (University of Chicago)

15:30 Coffee Break

Parallell Sessions

Special Events: Science on the Square/Madison Night Market (Free)

Friday 16 October

Registration and Check-In

Plenary Session: VI

7 Challenges in Supernova Neutrino Detection

Advancing neutrino astronomy depends upon detecting many types of neutrino sources and making connections between them. Here I discuss challenges in supernova neutrino detection and how addressing them benefits the larger field.

Speaker: John Beacom (ORCID)

8 IceCube Upgrade Status and Prospects

The IceCube Neutrino Observatory has been successfully operating for 15 years at the South Pole. During this time, IceCube has made many groundbreaking observations in neutrino astrophysics, including the discovery of a high-energy astrophysical neutrino flux; the Seyfert galaxy NGC1068 as a neutrino source candidate; and neutrinos from the Milky Way.
In the 2025/26 Antarctic field season, an extension to IceCube, known as the IceCube Upgrade, was deployed, consisting of 5 new strings instrumented with newly designed optical modules. These 5 new strings make up a dense infill in the center of the detector to target low energy neutrino events; the optical modules are spaced closer together than in IceCube, and contain multiple photomultiplier tubes. The increase in photocathode density allows for higher sensitivity at the GeV scale, resulting in improved capabilities for neutrino oscillations studies and low-energy astronomy. In addition to the optical modules, many calibration devices were deployed, which will study the properties of the glacial ice and detector response. In this talk, I will discuss the success of the Upgrade’s deployment season, as well give an outlook towards the science goals.

Speaker: Delaney Butterfield (University of Wisconsin-Madison)

10:30 Coffee Break

Plenary Session: VII

9 Status and outlook of KM3NeT and some recent KM3NeT/ORCA results on neutrino oscillations

The KM3NeT collaboration is constructing two neutrino telescope infrastructures in the Mediterranean Sea, ORCA for GeV-energy neutrinos, and ARCA for neutrinos with multi-TeV energies. In this presentation the progress of both infrastructures is discussed, as well as the outlook for completion. Via the path of data acquisition, data quality assessment, calibration and reconstruction, some recent results on measurements of neutrino oscillations and tau neutrino production are presented. We also discuss systematic uncertainties on these measurements, and how collaboration between different neutrino telescopes can help in reducing them.

Speaker: Paul De Jong (Nikhef and University of Amsterdam)

10 Searching for New Physics With High-Energy Astrophysical Neutrinos

High-energy neutrinos produced in collisions of protons in the atmosphere or near the vicinity of black holes bring unique opportunities to probe fundamental physics. The unprecedented energy ranges and distance traversed by these neutrinos have enabled the IceCube Neutrino Observatory to search for low-energy signatures of quantum gravity and new neutrino phenomena. In this colloquium, I will show the latest results for searches for high-energy neutrinos using IceCube and KM3NeT, a new neutrino detector being deployed in the Mediterranean Sea. Additionally, I will discuss how ultra-high-energy neutrino physics is expected to grow over the next decade and the development of a new neutrino telescope called TAMBO.

Speaker: Prof. Carlos Arguelles Delgado (Harvard University)

12:30 Lunch (on your own)

Plenary Session: VIII

11 Status of IceCube-Gen2

I will provide an overview of the IceCube-Gen2 observatory currently under development.

Speaker: Marek Kowalski (DESY / HU Berlin)

12 Panel Discussion

Moderated by Ke Fang, Marek Kowalski, Carlos Arguelles Delgado, and Dan Hooper