Moiré Magic

Moiré Magic


Highly tunable composite materials—with a twist.

The above animation shows the patterns created as two circles move across each other. Those patterns, created by two sets of lines offset from each other, are called moiré (pronounced mwar-AY) effects. As optical illusions, moiré patterns create neat simulations of movement. But at the atomic scale, when one sheet of atoms arranged in a lattice is slightly offset from another sheet, these moiré patterns can create some exciting and important physics with interesting and unusual electronic properties.

Mathematicians at the University of Utah have found that they can design a range of composite materials from moiré patterns created by rotating and stretching one lattice relative to another. Their electrical and other physical properties can change—sometimes quite abruptly, depending on whether the resulting moiré patterns are regularly repeating or non-repeating. Their findings are published in Communications Physics.

The mathematics and physics of these twisted lattices applies to a wide variety of material properties, says Kenneth Golden, distinguished professor of mathematics. “The underlying theory also holds for materials on a large range of length scales, from nanometers to kilometers, demonstrating just how broad the scope is for potential technological applications of our findings.”

 

Ken Golden

"We observe a geometry-driven localization transition that has nothing to do with wave scattering or interference effects, which is a surprising and unexpected discovery."

 

With a twist

Before we arrive at these new findings, we’ll need to chart the history of two important concepts: aperiodic geometry and twistronics.

Aperiodic geometry means patterns that don’t repeat. An example is the Penrose tiling pattern of rhombuses. If you draw a box around a part of the pattern and start sliding it in any direction, without rotating it, you’ll never find a part of the pattern that matches it.

Aperiodic patterns designed over 1000 years ago appeared in Girih tilings used in Islamic architecture. More recently, in the early 1980s, materials scientist Dan Shechtman discovered a crystal with an aperiodic atomic structure. This revolutionized crystallography, since the classic definition of a crystal includes only regularly repeating atomic patterns, and earned Shechtman the 2011 Nobel Prize in Chemistry.

Okay, now onto twistronics, a field that also has a Nobel in its lineage. In 2010, Andre Geim and Konstantin Novoselov won the Nobel Prize in Physics for discovering graphene, a material that’s made of a single layer of carbon atoms in a lattice that looks like chicken wire. Graphene itself has its own suite of interesting properties, but in recent years physicists have found that when you stack two layers of graphene and turn one slightly, the resulting material becomes a superconductor that also happens to be extraordinarily strong. This field of study of the electronic properties of twisted bilayer graphene is called “twistronics.”

Two-phase composites

In the new study, Golden and his colleagues imagined something different. It’s like twistronics, but instead of two layers of atoms, the moiré patterns formed from interfering lattices determine how two different material components, such as a good conductor and a bad one, are arranged geometrically into a composite material. They call the new material a “twisted bilayer composite,” since one of the lattices is twisted and/or stretched relative to the other. Exploring the mathematics of such a material, they found that moiré patterns produced some surprising properties.

“As the twist angle and scale parameters vary, these patterns yield myriad microgeometries, with very small changes in the parameters causing very large changes in the material properties,” says Ben Murphy, co-author of the paper and adjunct assistant professor of mathematics.

Twisting one lattice just two degrees, for example, can cause the moiré patterns to go from regularly repeating to non-repeating—and even appear to be randomly disordered, although all the patterns are non-random.  If the pattern is ordered and periodic, the material can conduct electrical current very well or not at all, displaying on/off behavior similar to semiconductors used in computer chips. But for the aperiodic, disordered-looking patterns, the material can be a current-squashing insulator, “similar to the rubber on the handle of a tool that helps to eliminate electrical shock,” says David Morison, lead author of the study who recently finished his Ph.D. in Physics at the University of Utah under Golden’s supervision.

This kind of abrupt transition from electrical conductor to insulator reminded the researchers of yet another Nobel-winning discovery: the Anderson localization transition for quantum conductors. That discovery, which won the 1977 Nobel Prize in Physics, explains how an electron can move freely through a material (a conductor) or get trapped or localized (an insulator), using the mathematics of wave scattering and interference. But Golden says that the quantum wave equations Anderson used don’t work on the scale of these twisted bilayer composites, so there must be something else going on to create this conductor/insulator effect. “We observe a geometry-driven localization transition that has nothing to do with wave scattering or interference effects, which is a surprising and unexpected discovery,” Golden says.

The electromagnetic properties of these new materials vary so much with just tiny changes in the twist angle that engineers may someday use that variation to precisely tune a material’s properties and select, for example, the visible frequencies of light (a.k.a. colors) that the material will allow to pass through and the frequencies it will block.

“Moreover, our mathematical framework applies to tuning other properties of these materials, such as magnetic, diffusive and thermal, as well as optical and electrical,” says professor of mathematics and study co-author Elena Cherkaev, “and points toward the possibility of similar behavior in acoustic and other mechanical analogues.”

Find the full study in Communications Physics.

 

by Paul Gabrielsen, first published in @TheU.

 

Living Legend

Toto Gets Stamped!


Filipino stamp of "Toto"

Distinguished Professor Baldomero Olivera is featured in the Filipino Postal Office’s “Living Legends” commemorative stamp series.

Affectionately referred to as “Toto,” Olivera has pioneered research on marine cone snails, demonstrating the therapeutic potential of their venom, already resulting in an FDA-approved drug. The University of Utah’s biochemistry and pharmacy departments (UofU Health) are currently expanding on some of this work.

His early research contributions include the discovery and biochemical characterization of E. coli DNA ligase, a key enzyme of DNA replication and repair that is widely used in recombinant DNA technology.

In a 2018 profile, Olivera was described as unconventional: “Not every molecular biologist would think to look in cone snail venom for potential therapeutics. But a long-held interest in the biological environment that surrounded him while growing up in the Philippines — and a habit of making unconventional choices — led Baldomero ‘Toto’ Olivera to do just that.”

After completing his Ph.D. at the California Institute of Technology and postdoctoral research at Stanford University, Olivera returned to the Philippines to establish his independent research program. Now at the School of Biological Sciences at the University of Utah, Olivera has discovered several peptides in snail venom that have reached human clinical trials. One has been approved for the treatment of severe pain.

 

Baldemaro Olivera

“I didn’t make choices that were conventionally considered wise at the time. The things that didn’t seem so wise at the time turned out to be okay.”

 

While building a productive research program, he also was developing new ways to educate and inspire future generations of scientists in the U.S. and the Philippines. As a Howard Hughes Medical Institute Professor, he has developed hands-on curricula that draw young students to science by teaching them about scientific principles they can observe in the organisms they see every day.

When Olivera was selected as one in the series of “Living Legends” commemorative stamps, graduate student Paula Florez Salcedo in the Olivera lab tweeted “He is a living legend, and I can’t believe I get to learn from him!”

When asked by an interviewer to list something that Olivera knows now in his career as a scientist that he wished he’d known earlier, he says,

“I didn’t make choices that were conventionally considered wise at the time. When I was going back to the Philippines, everyone was saying ‘Why are you doing that? You’re ruining your scientific career.’ But that turned out to be very good for my scientific career because I started working with cone shells. So I really have no major regrets, I must say. The things that didn’t seem so wise at the time turned out to be okay.”

In science and technology, the post office selected to honor national scientist and physician Ernesto Domingo along with the internationally recognized Olivera.

“They have dedicated their lives and talents to the Filipino people,” Postmaster General Norman Fulgencio said in February when the announcement was made. “They deserve to be immortalized in our stamps to inspire not only Filipinos, but every nationality who will see our stamps.”

The post office turned over to representatives of the honorees the framed stamps in tribute to them. “The stamps we issued today are not only meant for delivery of letters, but more importantly to deliver hope,” Fulgencio said.

Furthermore, the stamps “symbolize what Filipinos are capable of — wherever we are, whoever we are up against and whatever it takes,” he said.

 

by David Pace, first published at biology.utah.edu.

 

Faculty Giving

Faculty Giving


My wife Tanya Williams and I are happy to be able to provide a planned gift to the School of Biological Sciences at the University of Utah. We moved to Utah in 2010 to establish my Biodiversity and Conservation Ecology laboratory. I am thankful for the research, teaching and service opportunities provided to me by the University of Utah and Tanya is grateful to be able to serve her patients at the U’s School of Medicine.

Our work has benefited greatly from the generosity, resources and collegiality provided to us by the U, its faculty, alumni and other benefactors. This support has enabled me to study, conserve and teach about the world’s endangered, biodiversity and helped Tanya to provide healthcare to the underserved people of this beautiful state.

We hope to “pay it forward” by providing a modest legacy gift for SBS. Planned gifts of this kind will help SBS continue to attract and support the best PhD students in biodiversity research, conservation biology, environmental science, ornithology and wildlife ecology during this time of rapid and devastating global change that requires all hands on deck.

We hope you will join us in making a legacy gift to the School of Biological Sciences.

Sincerely,
Çağan H. Şekercioğlu, PhD and Tanya M. Williams, MD

 

Interactive Forest Maps

Wildfire, Drought & Insects


Dying forests in the western U.S.

Threats impacting forests are increasing nationwide.

Planting a tree seems like a generally good thing to do for the environment. Trees, after all, take in carbon dioxide, offsetting some of the emissions that contribute to climate change.

But all of that carbon in trees and forests worldwide could be thrown back into the atmosphere again if the trees burn up in a forest fire. Trees also stop scrubbing carbon dioxide from the air if they die due to drought or insect damage.

The likelihood of those threats impacting forests is increasing nationwide, according to new research in Ecology Letters, making relying on forests to soak up carbon emissions a much riskier prospect.

“U.S. forests could look dramatically different by the end of the century,” says William Anderegg, study lead author and associate professor in the University of Utah School of Biological Sciences. “More severe and frequent fires and disturbances have huge impacts on our landscapes. We are likely to lose forests from some areas in the Western U.S. due to these disturbances, but much of this depends on how quickly we tackle climate change.”

 

William Anderegg

"We’ve seen devastating fire seasons with increasing severity in the past several years. Generally, we expect the western U.S. to be hit hardest."

 

The researchers modeled the risk of tree death from fire, climate stress (heat and/or drought) and insect damage for forests throughout the United States, projecting how those risks might increase over the course of the 21st century.

See their findings in an interactive map at carbonplan.org.

By 2099, the models found, that United States forest fire risks may increase by between four and 14 times, depending on different carbon emissions scenarios. The risks of climate stress-related tree death and insect mortality may roughly double over the same time.

But in those same models, human actions to tackle climate change mattered enormously—reducing the severity of climate change dramatically reduced the fire, drought and insect-driven forest die-off.

“Climate change is going to supercharge these three big disturbances in the U.S.,” Anderegg says. “We’ve seen devastating fire seasons with increasing severity in the past several years. Generally, we expect the western U.S. to be hit hardest by all three of these. And they’re somewhat interconnected too. Really hot and dry years, driven by climate change, tend to drive lots of fires, climate-driven tree mortality and insect outbreaks. But we have an opportunity here too. Addressing climate change quickly can help keep our forests and landscapes healthy.”

The study is published in Ecology Letters and was supported by the National Science Foundation, U.S. Department of Agriculture, David and Lucille Packard Foundation and Microsoft’s AI for Earth.

Find the full study at Ecology Letters.

 

by Paul Gabrielsen, first published at @TheU.

 

Societal Impact Scholar

Societal Impact Scholar


Ken Golden Named U Presidential Societal Impact Scholar

President Taylor R. Randall has named Ken Golden, Distinguished Professor of Mathematics, as an inaugural recipient of the University of Utah Presidential Societal Impact Scholar Award.

Dr. Golden and four other scholars are a select group of faculty. Recognized as experts in their respective fields and disciplines, they share and translate their scholarship, research, creative activities and ideas with opinion leaders, policy makers, the public and other audiences outside the university and in ways that can transform society.

 

Ken Golden

"Dr. Golden is among the rare group of top-level mathematical scientists who is able to reach to the broader public about one of the central issues of our time."

 

Golden is a brilliant expositor and a passionate advocate for public awareness of our changing climate and the critical role of mathematics in climate modeling. He has given over 40 invited public lectures since 2008, and over 500 invited lectures since 1984. His public lectures emphasize the rapid and significant loss of Arctic sea ice, and how mathematics is helping us predict the future of the Earth’s polar marine environment. Dr. Golden is among the rare group of top-level mathematical scientists who is able to reach to the broader public about one of the central issues of our time.

From tackling the social determinants of health and wellness, to addressing the underlying causes of crime and poverty, to designing interventions to curb poor air and water quality, to helping better inform public debate on society’s most pressing issues, these scholars’ works have a positive impact on people and institutions and help make our world a better, more equitable and enjoyable place in which to live.

The 2022 cohort of impact scholars are:
Kenneth Golden, Distinguished Professor, Department of Mathematics
RonNell Andersen Jones, Professor, College of Law
Michelle Litchman, Assistant Professor, College of Nursing
Susie Porter, Professor, College of Humanities and the School for Cultural and Social Transformation
Paisley Rekdal, Distinguished Professor, Department of English

The Presidential Societal Impact Scholar Award was conceived by and is supported by a gift from University of Utah Professor Randy Dryer.

 

by Michele Swaner, first published at math.utah.edu.

 

National Academy of Sciences

National Academy of Sciences


Valeria Molinero elected as a member of the National Academy of Sciences.

Molinero is the Jack and Peg Simons Endowed Professor of Theoretical Chemistry and the director of the Henry Eyring Center for Theoretical Chemistry. She is a theoretical chemist and uses computer and statistical models to explore the science of how crystals form and how matter changes from one phase to another down to the atomic scale.

Much of her work has involved the transition between water and ice and how that transition occurs in the formation of clouds, in insects with antifreeze proteins, and in food products, especially those containing sugars. Her work has implications for any process in which control of the formation and growth of ice crystals is critical, including snowmaking at ski resorts, protection of crops from freezing, preservation of human organs and tissue for transplant, and production of ice cream and gelato, her favorite food. In 2020, she and her international colleagues demonstrated that the smallest possible nanodroplet of water that can freeze into ice is around 90 molecules, a finding that earned them the 2020 Cozzarelli Prize from the journal Proceedings of the National Academy of Sciences.

She is a fellow of the American Academy of Arts & Sciences and recipient of several U awards, including the Distinguished Scholarly and Creative Research Award in 2019, the Extraordinary Faculty Achievement Award in 2016, the Camille Dreyfus Teacher-Scholar Award in 2012 and the College of Science Myriad Faculty Award for Research Excellence in 2011. She has also been honored by the Beckman Foundation with its Young Investigator Award, and by the International Association for the Properties of Water and Steam with its Helmholtz Award.

Valeria Molina

"There’s satisfaction that comes from seeing someone grow from the beginning of the Ph.D. into an accomplished researcher."

 

Valeria heard about her election between the news of a new publication with postdoctoral scholar Debdas Dhabal and preparations for a doctoral student’s dissertation defense. She received a phone call from colleague Dale Poulter, a distinguished professor emeritus and National Academy of Sciences member, to announce her election. “I was shocked,” she says. “To say it was a surprise would not do it justice. It was fantastic.”

Minutes later, she went into the dissertation defense, reflecting on the range of accomplishments represented by the publication, the election and the defense. “All the research is made essentially there, in the work of the students and postdocs,” she says. “There’s satisfaction that comes from seeing someone grow from the beginning of the Ph.D. into an accomplished researcher.”

Molinero is among 120 U.S. scientist-scholars and 30 foreign associates elected at the Academy’s Annual Meeting in Washington, D.C. She joins 16 other current University of Utah researchers who’ve been elected to the Academy. The National Academies, which also include the National Academy of Engineering and National Academy of Medicine, recognizes scholars and researchers for significant achievements in their fields and advise the federal government and other organizations about science, engineering and health policy. With today’s elections, the number of National Academy of Sciences members stands at 2,512, with 517 foreign associates.

Read more at nasaonline.org.

 

Past & Present

  • National Academy of Sciences:
    Brenda Bass, Cynthia Burrows, Mario Capecchi, Dana Carroll, Thure Cerling, James Ehleringer, Kristen Hawkes, James O’Connell, Baldomero “Toto” Olivera, C. Dale Poulter, Peter Stang, Wesley Sundquist, Polly Wiessner, Henry Harpending, Jesse D. Jennings, Erik Jorgensen, Cheves Walling, Sidney Velick, John R. Roth, Josef Michl, Ray White, Julian Steward, Jeremy Sabloff, Henry Eyring and Louis Goodman and Mary C. Beckerle.
  • National Academy of Engineering:
    Jindrich Kopecek, R. Peter King, Adel Sarofim, Sung Wan Kim, Gerald Stringfellow, Donald Dahlstrom, George Hill, Jan D. Miller, Milton E. Wadsworth, Thomas G. Stockham, John Herbst, Stephen C. Jacobsen, Willem J. Kolff, Alex G. Oblad, Anil Virkar and William A. Hustrulid.
  • National Academy of Medicine:
    Mario Capecchi, Wendy Chapman, Sung Wan Kim, Vivian Lee, Baldomero “Toto” Olivera, Stephen C. Jacobsen, Eli Adashi, Paul D. Clayton and Homer R. Warner.

National Academy of Sciences

National Academy of Sciences


Erik Jorgensen elected as member of the National Academy of Sciences.

When explaining his work, Erik Jorgensen, a geneticist who studies the synapse, can transport you to an almost galactic place–the observable universe of the brain. “Synapses are contacts between nerve cells in your brain,” says the School of Biological Sciences’ distinguished professor and Howard Hughes Medical Institute Investigator who May 3, 2022 was elected to the National Academy of Sciences (NAS).

“You have trillions of them. Think of all the stars you can see on a moonless night on Bald Mountain,” he continues, referring to the 11,949-foot peak in the nearby Uinta Mountains. ‘Multiply that by 100 billion. I will give you a few minutes to do the calculation. …That’s how many synapses you have – the brain can hold and process a lot of information with all of those synapses. Your grandmother lives there.” Scientists want to know how synapses work, says Jorgensen, “understand how they change to store a memory, and how they become corrupted when we forget, or why they die as we pass into dementia.”

Lighting the way for a future scientist.

"It ends up that light is too big to see the structure of a synapse. That is why we use a different subatomic particle-an electron-to visualize the structure of the synapse. We use electron microscopes."

 

As of 2020, Jorgensen has been a collaborator in the National Science Foundation-funded Neuronex 2 Project, and he knows what it takes to understand these elusive, minute gaps between nerve cells. “We need to be able to see them,” he says, “to study their architecture, and track the proteins in the synapse. How can we do that? It ends up that light is too big to see the structure of a synapse. Light is made of photons, and photons are–well, too light–they have no mass; they vibrate too much to detect objects smaller than their vibrations. That is why we use a different subatomic particle-an electron-to visualize the structure of the synapse. We use electron microscopes.”

Along with Jorgensen, the international consortium includes scientists at the University of Texas in Austin and the UofU’s Bryan Jones who studies neural connections in the retina at the Moran Eye Center’s Marclab for Connectomics. The four interdisciplinary teams share reagents, methods and data to work together to characterize the formation of synapses, their function and their decline using electron microscopes.

“Biology is experiencing a great expansion in electron microscopy,” says Jorgensen,”because of some quite amazing improvements in the capabilities of electron microscopes. We can move in closer-advancements in resolution allow us to determine the atomic structure of protein complexes. Or we can stand back to see vast fields of synapses and their interconnections.

“The University of Utah and its leadership have invested in these new technologies, and we have become a leading institution in the world exploring this new terrain of biology.” Jorgensen and Jones are part of a collection of teams receiving more than $50 million over five years as part of the NSF’s Next Generation Networks for Neuroscience program (NeuroNex). A total of 70 researchers, representing four countries, will investigate aspects of how brains work and interact with the environment around them.

Erik Jorgensen's election to the NAS, arguably the most prestigious award of its kind, speaks to the kind of mind-blowing inquiry into neurology he's known for. It also validates Jorgensen's inner galactic allusion to locating where your grandmother suffering from severe dementia lives along with "your childhood friends, embarrassment, fear, love, and hate."

Read more at nasaonline.org.

 

By David Pace, first published @ biology.utah.edu.

 

NSF Fellowship

NSF Postdoctoral Research Fellowship


Eamon Quinlan-Gallego, receives a Mathematical Sciences Postdoctoral Research Fellowship from the National Science Foundation.

The three-year fellowship is awarded to support future leaders in mathematics and statistics by helping them participate in postdoctoral research that will enhance their development. “Receiving this fellowship is an incredible honor, and it will allow me to dedicate myself to research full-time for four semesters and extend my stay in Utah for an extra year. It will also give me funds to travel to conferences and visit collaborators,” he said.

Quinlan-Gallego studies solutions to polynomial equations and their singularities. For example, in pre-calculus, the equation y = x^2 defines a parabola in the plane. This parabola is smooth—it doesn’t have any sharp corners; however, occasionally, polynomial equations can fail to be smooth. These non-smooth points, called singularities, are ubiquitous across mathematics, and their study is a fundamental problem.

Eamon Quinlan-Gallego

"Receiving this fellowship is an incredible honor, and it will allow me to dedicate myself to research full-time for four semesters and extend my stay in Utah for an extra year."

 

Typically, Quinlan-Gallego uses two different techniques to study these singularities. First, he can associate certain differential equations to them whose behavior allows them to be classified in different ways. Second, he can study singularities using “modulo-p.” He fixes a prime number (usually denoted by p, but in this case, for example, we could use p = 5). Working “modulo-5” means that when he looks at a polynomial equation, like y^3 = x^2, instead of thinking about it in the real-number system (as you would in pre-calculus), he thinks of it in clock arithmetic. This means that he does all of the algebra using a clock with 5 hours. For example, if our clocks had 5 hours, and it was 4 o’clock and 2 hours pass, it is 1 o’clock. In clock arithmetic, we would say that 4 + 2 = 1. Similarly, 4 x 2 is usually 8 but in our clock, we have 4 x 2 = 3. “By working in this clock arithmetic, we lose all of the “geometry,” but we gain a host of other tools we can use, and the hope is that as the prime p selected gets larger and larger, the behavior of the singularity modulo-p approaches the real behavior,” he said. He also likes to combine these two techniques and think about differential equations modulo-p.

He was good at math as a kid but until he was a senior in high school, he thought he would become a biologist. Then two things happened: he realized he only wanted to study biology because the idea of going to remote islands to look at creatures no one had seen before sounded cool, but learning about all the chemical reactions going on in the mitochondria wasn’t so exciting--and he read Stephen Hawking’s book A Brief History of Time and became fascinated by how mathematics is used to learn about things that are far away in space and time. At that point, he switched from studying biology to physics. The jump from physics to mathematics was much more straightforward when he realized he was enjoying his math classes more than experimental physics.

Quinlan-Gallego was raised in Spain—his mother is Spanish and his father is American. After high school, he left Spain to study in Scotland at the University of Glasgow. “There was this great program for citizens of the European Union that allowed me to study in Scotland for free,” he said. “I had a wonderful time in Glasgow, and I was given so many amazing opportunities.” During his undergraduate years, he also participated in an exchange program at the National University of Singapore for a year.

Once he completed his bachelor’s degree, he knew he wanted to come to the U.S. for graduate school. He was accepted to the University of Michigan and began working under Professor Karen Smith, who serves as the William Fulton Distinguished University Professor of Mathematics. He also spent more than a year in Tokyo, again as an exchange graduate student, at the University of Tokyo.

He’s looking forward to continuing his work at the U. “The department has many experts in modulo-p methods and a host of other very interesting topics, so I’m looking forward to learning as much as possible from them and moving forward in my research.”

 

by Michele Swaner, first published @ math.utah.edu

 

NSF Fellowship

NSF Postdoctoral Research Fellowship


Alex Rasmussen receives a Mathematical Sciences Postdoctoral Research Fellowship from the National Science Foundation.

The three-year fellowship is awarded to support future leaders in mathematics and statistics by helping them participate in postdoctoral research that will enhance their development.

Rasmussen is a Research Assistant Professor in the department. “I’m very grateful to be recognized for my research and to the people who helped me along the way, including my advisors, collaborators, mentors, and teachers,” he said. “The award will allow me to devote more time to my research program. In addition, it will enable me to take on more activities to serve the math community, such as mentoring undergraduates and organizing conferences.”

Rasmussen’s work focuses on symmetries of geometric objects. Specifically, he’s interested in symmetries of spaces that are “negatively curved.” “The geometry of negatively curved spaces is quite unlike that of our own space, and it makes them exotic and also very beautiful,” he said.

A bunch of symmetries form a group, and a group can be thought of as symmetries of many different negatively curved spaces at the same time. A large part of Rasmussen’s research is spent on classifying the different spaces associated to one group. He finds the subject interesting because it allows him to draw pictures, engage his creative and aesthetic senses, and use tools from other fields, such as commutative algebra.

Alex Rasmussen

"I’m very grateful to be recognized for my research and to the people who helped me along the way, including my advisors, collaborators, mentors, and teachers."

 

In high school, he wasn’t especially interested in math. He did well at it but found it somewhat dry and mechanical. His first math class at Colby College was a multivariable calculus class taught by Scott Taylor, Associate Professor and Department Chair. Taylor used pictures of curves and surfaces in his teaching. This was a revelation to Rasmussen, who began to discover the beauty, depth, and creativity of math. From that point on, he took more math classes.

He received a bachelor’s degree in mathematics and began a graduate program at the University of California Santa Barbara, where he received a master’s degree. He obtained a Ph.D. in mathematics from Yale University in 2020.

He has a few research goals he’d like to work on over the next few years. These include classifying hyperbolic actions of metabelian groups and classifying geodesic laminations on infinite type surfaces. Metabelian groups are a wide class of relatively simple groups that can still have complicated hyperbolic actions. Geodesic laminations are 1-dimensional objects on surfaces consisting of long straight lines interacting in complicated ways. “These are pretty hard problems that will keep me busy for a while. Along the way, many other related problems will pop up naturally,” he said.

 

by Michele Swaner, first published @ math.utah.edu

 

Women in Mathematics

Women in Mathematics


Last spring, the Math Department’s student chapter of the Association for Women in Mathematics (AWM) planned a conference, with speakers, mini courses, breakout sessions, and professional development panels. About 60 participants were expected. Unfortunately, when the pandemic hit in March, everything changed, and the conference was canceled.

Despite the setback, the chapter still moved forward and will host a series of online activities and communications for attendees. In recognition of these remarkable efforts, the chapter was recently selected as the winner of the 2020 AWM Student Chapter Award for Scientific Excellence. Christel Hohenegger, associate professor of mathematics, serves as faculty advisor for the chapter.

"We are very thankful and excited to have won this award and receive national recognition,” said Claire Plunkett, vice president of the chapter for 2020-2021. “This is a national award from the AWM, and we are one of more than a hundred student chapters, so it’s a great honor to be chosen. We feel the award reflects how our chapter's activities have continued to grow and gain momentum over the past several years, and we’re excited to continue to sponsor events and expand our activities.”

For the academic year, the chapter has invited four speakers and all talks will be held on Zoom. Confirmed speakers include Nilima Nigam, professor of mathematics at Simon Fraser University; Kristin Lauter, principal researcher and partner research manager for the Cryptography and Privacy Research group at Microsoft Research; and Christine Berkesch, associate professor of mathematics at the University of Minnesota. The annual conference has been rescheduled for June 2021.

In addition, the chapter will continue to host joint monthly lunch discussions with the SIAM (Society for Industrial and Applied Mathematics) student chapter; a professor panel in which faculty research is shared with students; joint LaTeX (a software system for document preparation) workshops held with the SIAM student chapter; a screening of a documentary called Picture aScientist, a discussion co-hosted with other women in STEM groups; and bi-weekly informal social meetings. For more information about the U’s AWM chapter, visit http://www.math.utah.edu/awmchapter/.

 - first published by the Department of Mathematics