Neutrinos are weakly interacting particles that are able to travel undeflected through the cosmos. The IceCube Neutrino Observatory and the KM3NeT Astroparticle Research with Cosmics in the Abyss (ARCA) telescope (still under construction) are cubic-kilometer-scale neutrino telescopes that search for the sources of these astrophysical neutrinos in hopes of uncovering the origin of ultra-high-energy cosmic [...]
Read the full article at: https://wipac.wisc.edu/probing-the-connection-between-the-highest-energy-astrophysical-neutrinos-and-ultra-high-energy-cosmic-rays/News Archives
Welcome, Prof. Jakob Moritz!
String theorist Jakob Moritz joined the faculty as an assistant professor of physics on January 1, 2025. He joins us from CERN where he has been a postdoc for just over a year. Previously, he was a postdoc for four years at Cornell University, and before that, he earned his PhD from the University of Hamburg and DESY.
Please give a general overview of your research.
I work on string theory, a theoretical framework for quantum gravity. It is the only known approach that consistently combines quantum mechanics and Einstein’s theory of gravity. Physicists have struggled for decades to reconcile these two fundamental theories, and string theory achieves this unification. Sometimes called “the theory of everything,” string theory addresses physical phenomena at arbitrarily high energies. While the nickname may sound a bit grandiose, it highlights the theory’s incredible scope.
However, while the field equations of string theory have solutions that are relatively easy to study, these don’t resemble our universe. My research focuses on going beyond these “easy” solutions to find ones that better match the universe we observe. By doing so, I aim to uncover insights into the origins of the peculiar laws of physics governing our universe.
Something that I find particularly interesting is dimensionless constants of nature. These constants are significant because they are independent of a choice of units. For example, the ratio of the electron’s mass to the top quark’s mass is a dimensionless number — about 0.000003, which is remarkably small! There are many such constants whose values are determined experimentally, yet we lack a theoretical explanation for them.
In the early 20th century, particle physicists didn’t focus much on questions like, “Why are the constants of nature what they are, and not something else?” But with string theory, we can begin to address this. My work seeks to identify solutions of string theory in which these numbers align with experimental values. Another well-known example is the energy density of the vacuum, or dark energy. Despite being the dominant energy source in the universe today, dark energy is extraordinarily small in natural units — just 10^{-120} when compared to the natural energy scale of quantum gravity. This discrepancy, known as the cosmological constant problem, is something I find deeply intriguing. How can such a small value arise? Why isn’t it zero? Similarly, why is the Higgs mass so small? These are the kinds of profound questions I aim to explore through string theory.
What are one or two main projects you’ll have new group members work on?
One major project will involve finding the Standard Model of particle physics within string theory. This is something I am already working on, but having more hands on deck would be invaluable. The goal is to “engineer” realistic laws of particle physics — either the Standard Model or something close to it — as solutions of string theory. This work is crucial for addressing the electroweak hierarchy problem: why is the Higgs mass so unnaturally small? Currently, no one has a clear explanation for this.
Technically, this involves a lot of geometry. String theory predicts the existence of extra dimensions, which are both a blessing and a curse. They must be small enough to have remained unobservable, yet they also determine the physical laws we experience at larger scales. Much of our work will focus on understanding these geometries — particularly how certain objects, called branes, wrap around features like circles in these spaces — and calculating the resulting physical laws.
What attracted you to Madison and the university?
I really appreciate the breadth of the theory department here. String theory is a vast field, encompassing topics that range from almost pure mathematics to particle phenomenology. Because my work leans toward the phenomenological side, it intersects with many other areas of theoretical physics, including cosmology, particle physics, and applied mathematics. Being at a large place like Madison, with its diverse and talented faculty, is incredibly exciting.
Additionally, I know that Madison attracts outstanding students who are eager to work on string theory and particle physics. That’s something I’m looking forward to as well!
What is your favorite element and or elementary particle?
Neutrinos are cool because they’re almost massless. For a long time, they were thought to have zero mass, as predicted by the Standard Model of particle physics. But experiment has revealed otherwise! This discovery hints strongly at new physics at high energies.
What hobbies and interests do you have?
I love music! I play piano and guitar, and music is a big part of my life, especially since my partner is also a musician. I also enjoy sailing. While at Cornell, I spent summers sailing and participated in weekly competitive races, which were incredibly fun. I know that sailing is also a thing here — I look forward to getting back on the water!
Baha Balantekin honored at neutrino astrophysics workshop
The illustrious career of Baha Balantekin, the Eugene P. Wigner professor of physics at UW–Madison, was celebrated recently at the Neutrinos in Physics and Astrophysics Workshop through the Network for Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) Physics Frontier Center.
Balantekin works at the intersection of nuclear physics, particle physics, and astrophysics. For much of his career, he has studied theoretical aspects of neutrinos originating in the Sun, supernovae, or neutron star mergers. He has helped pioneer the field known as neutrino astronomy.
“Even just a few decades ago, if you said ‘neutrino astronomy,’ most physicists would have snickered. That’s because astronomy is about observations and neutrinos are almost impossible to detect,” says John Beacom, PhD ’97, distinguished professor of physics and astronomy at the Ohio State University. “But, over time, physicists have helped to make this seemingly impossible field into something real and vibrant. The observations of astrophysical neutrinos that have been made have been essential to understanding our Sun, supernovae, and distant galaxies.”
Balantekin and George Fuller, a distinguished professor of physics at the University of California, San Diego, have helped lead the field of neutrino astrophysics through both their scientific work and their mentoring of junior scientists. To honor both scientists’ significant and ongoing contributions to the field, three of their former students organized the workshop: Beacom, a former student of Balantekin’s, and Fuller’s former students Gail McLaughlin, distinguished university professor of physics at North Carolina State University and Yong Zhong Qian, professor of physics and astronomy at the University of Minnesota. The event was held Jan 16-18 at the University of California, Berkeley.
Francis Halzen, a current colleague of Balantekin’s at UW–Madison, was one of the speakers. Other attendees included UW–Madison physics professor Pupa Gilbert and professor emerit Sue Coppersmith.
John Beacom and Pupa Gilbert contributed significantly to this story
Dan McCammon awarded Distinguished Career Prize
Congrats to Prof. Dan McCammon for earning the Distinguished Career Award from The American Astronomical Society’s (AAS) High Energy Astrophysics Division (HEAD) for his pioneering work on the development of microcalorimeters that has led to breakthroughs in X-ray astronomy and on soft diffuse X-ray background.
The HEAD Distinguished Career Prize is awarded at the time of the Division Meeting to recognize an individual high-energy astrophysicist who has made outstanding contributions to the field of high energy astrophysics throughout their career. Outstanding contributions include a body of important research results (observational, theoretical or experimental) which have led to ground-breaking results in high-energy astrophysics, and/or a career of mentorship to a new generation of high-energy astrophysicists, especially if this mentorship helped to support under-represented or under-resourced scientists and increased the diversity of the HEA community. The winner gives an invited talk at the Divisional Meeting in the award year. The prize carries a cash award of $1500.
AAS announced many 2025 prizes today; the full list can be found at their website.
This post is adapted from the AAS news release and website linked within the text.
UW physicists use Purdue supercomputer to challenge traditional turbulence theory for space and climate modeling
Read the full article at:
https://www.rcac.purdue.edu/news/6956
Qolab, the first UW–Madison-incubated quantum startup, joins the Chicago Quantum Exchange
Read the full article at:
https://chicagoquantum.org/news/qolab-first-uw-madison-incubated-quantum-startup-joins-cqe
Physics major Caleb Youngwerth wins poster prize at APS Eastern Great Lakes meeting
Congrats to physics, astronomy-physics, mathematics and french major Caleb Youngwerth on winning the Meeting Award for Undergraduate Student Poster at the Fall 2024 meeting of the Eastern Great Lakes Section of APS!
Youngwerth’s poster, entitled, “Harnessing Molecular Simulation of the DLVO Potential to Engineer New Battery Technologies,” was presented at the meeting held October 18-19 at Marietta College in Ohio. The work was conducted in the chemical and biological engineering group of Prof. Rose Cersonsky.
The award was announced at the meeting and comes with a cash prize.
For more info, read Chemical and Biological Engineering’s story about Caleb: https://engineering.wisc.edu/blog/student-wins-award-for-research-on-colloidal-gels/
Physics awarded need-based graduate fellowships by U.S. Department of Education
This fall, the U.S. Department of Education awarded the UW–Madison department of physics with Graduate Assistance in Areas of National Need (GAANN) fellowships. These fellowships will assist graduate students with strong academic records who demonstrate financial need. Fellows must also demonstrate a commitment to improving their teaching. GAANN has identified seven Areas of National Need, including physics.
“Advances in physics research have far-reaching implications: they strengthen scientific leadership, lead to innovations, address STEM workforce needs, and ultimately benefit society as a whole,” says Tulika Bose, professor of physics and GAANN project director at UW–Madison. “The fellowship opportunities awarded through this program will enable us to provide new opportunities to deserving incoming or continuing students. We hope it will attract low-income students into our graduate program since the attractiveness of a fellowship offer could potentially tip the balance towards graduate study in physics for some of the extremely bright undergraduate physics majors who otherwise might decide to pursue careers in non-physics disciplines.”
Nine GAANN fellowships will be available annually for three years to current or incoming physics doctoral students. Students selected for fellowships must demonstrate both financial need and an interest in improving their physics teaching, and they may pursue any area of physics research. The department is working with the Office of Financial Aid to assess need.
Students must complete at least one academic year of supervised training in instruction at the undergraduate or graduate level at the schedule of at least one-half-time teaching assistant. They can choose from several options for enhancing their teaching portfolio by taking advantage of teaching assistant training sessions, trainings with the Physics Learning Center, or Delta Program certification or courses. They will also be provided professional development activities designed to enhance their skills and build their professional networks
The UW–Madison Graduate School will fund one of the nine fellowships as well as provide funds for professional society membership and conference attendance. The College of Letters & Science and the Department of Physics will support recruiting activities and fund a program evaluation to be conducted by the Wisconsin Center for Education Research.
Current or incoming students can learn more about the Physics GAANN program at https://www.physics.wisc.edu/graduate/phd-program/gaann/.
The GAANN Fellows program is supported by a grant from the U.S. Department of Education (PHYSGRAD-AID: PHYSics GRADuate Fellowship for Accelerating Innovation & Discovery – Award # P200A240159), the University of Wisconsin–Madison Graduate School, the College of Letters & Science, and the Department of Physics.
U.S. Cyber Command visit highlights UW–Madison’s leadership in cyber research and education
UW–Madison plays a leading role as a research and education partner for national cybersecurity. It reinforced this commitment recently by welcoming to campus a delegation from the United States Cyber Command (USCYBERCOM), which is responsible for the Department of Defense’s cyberspace capabilities.
Read the full article at: https://news.wisc.edu/u-s-cyber-command-visit-highlights-uw-madisons-leadership-in-cyber-research-and-education/Welcome, Prof. Melinda Soares-Furtado!
Melinda Soares-Furtado, an observational astronomer, joined the UW–Madison faculty this fall on a joint appointment in the astronomy and physics departments. She earned her undergrad degree at UC-Santa Cruz, then her doctorate in astrophysical sciences at Princeton. In 2020, she began a postdoc apppointment in UW–Madison astronomy, where she subsequently was awarded a NASA Hubble Postdoctoral Fellowship.
Please give an overview of your research.
I’m interested in stars and the planets that orbit them. So far, here at Madison, my team has detected and characterized two young, nearby planets. I want to know as much as possible about the worlds we discover, and part of that investigation includes knowing as much as possible about the stars the planet orbits. We have lines of research focused on the stellar age, its local environment (is it isolated or moving with a large collection of stars?), and its activity. Is the planet orbiting the star in a docile, stable environment or one that makes it more challenging to retain an atmosphere? How can we use follow-up observations both on the ground and with space-based facilities to get new insights into these worlds? Can instruments like HST and JWST offer a glimpse of the planet’s atmospheric evolution? Given the ever-expanding number of worlds we have discovered over the past three decades, how unusual is our own Solar System?
What are one or two main projects your group will work on first?
I have a broad range of research interests, so one or two main projects is sort of hard to narrow down. Right now, I’m most excited about the young worlds we have found in the Solar Neighborhood and the added context we can get with additional observations. I’d like to know the mass of the mini-Neptune-sized planet we recent found and here at UW-Madison, we have access to the institutional resources that will allow us to make this measurement! This planet is compelling, because it is found at the upper edge of a distribution known as the “radius valley”. The mass can help us understand the eventual fate of this young planet orbiting an active M dwarf star. I’m also interested to see what we learn with JWST and HST about an Earth-sized planet we found orbiting a Sun-like star. Will we see signs of atmospheric outgassing?
Putting on my stellar astronomer hat, I’m also really intrigued by what more we can learn about stars and ways in which we can better estimate their ages and evolutionary histories. Again, here at UW-Madison, our institutional access makes it possible to probe some of these mysteries in impactful ways — largely due to our access to WIYN/NEID, which offers high-precision measurements of a star’s shifting spectral lines.
What attracted you to Madison and the University?
I was drawn to the University of Wisconsin–Madison for its exceptional research environment and the wealth of opportunities available for collaboration. The Department of Astronomy is not only broad in its research pursuits — it is also notably collegiate, fostering a collaborative and supportive atmosphere among faculty, students, and staff. Access to cutting-edge facilities such as WIYN/NEID, SALT, and NOEMA was a strong attraction, as these instruments enable a range of high-impact research opportunities, from precise stellar characterization to molecular gas studies.
I was also excited to join the Wisconsin Center for Origins Research (WiCOR) collaboration. The Wisconsin Center for Origins Research (WiCOR) is a multidisciplinary center at UW-Madison designed to unite researchers from diverse scientific departments, including astronomy, chemistry, geoscience, and biology, to study the origins of life in the universe. Recently established with a dedicated research space, WiCOR not only focuses on cutting-edge projects — such as investigating potentially habitable exoplanets with the James Webb Space Telescope—but also emphasizes public outreach and educational initiatives, making it a leader in origins research and science communication.
What is your favorite element and/or elementary particle?
I think everyone in the department knows I have a fondness for lithium! As a PhD student, I worked on the signatures of stars that ingest their planetary companions, finding that lithium excess can sometimes be observed. I predicted which stars which show such an enhancement, and this was verified in large abundance surveys a year later. Lithium is a useful flag for engulfment, because it is readily destroyed in the interiors of forming stars, but never reaches temperatures required for destruction in planets. It therefore can be one to two orders of magnitude higher in these less massive bodies. If a star ingests a planet later in its evolution, that signature is sometimes observable! I like to hunt for such lithium-rich stars and then explore other aspects of their chemistry to better understand the cause of their enrichment.
What hobbies and interests do you have?
I like to garden, read, and spend time with my family. I often hike the Grady Tract Loop not far from my home. I have an app I use to identify plants, fungi, and wildlife. My daughter and I like to use it when we go on walks together. I have a fondness for photography. During my undergraduate years, I worked with my sister as a family photographer in California. These days I mostly photograph plants and landscapes. I also love to dance cumbia, salsa, and bachata. I danced often when I was growing up and even spent some time on a salsa choreography team in San Jose, California. I also collect and read vintage textbooks — most of my favorites are from the 1930s.