Born in Costa Rica, Xenia grew up without envisioning a career in academia. Initially pursuing biology at university, it was during her first year that she discovered her passion for mathematics and physics. “I didn’t have the idea that I could be an academic,” she shares. This pivotal realisation led her to switch to physics, laying the foundation for her distinguished academic career. After completing a master's in Costa Rica, Xenia embarked on a transformative journey to the University of Texas for her PhD where she met Philip. There, she made significant strides in her research, focusing on Calabi-Yau manifolds and mirror symmetry - topics that set the stage for her future influential contributions to string theory. Beyond her academic accomplishments, Xenia has also remained actively involved in fostering mathematical physics in Latin America and other global scientific communities.

Philip’s path was more straightforward. "By the time I was in high school, I knew I would go into something mathematical," Philip recalls. His fascination with mathematics and theoretical physics deepened during his school years in the UK, leading him to Cambridge, where he specialised in theoretical physics. Later, at Oxford, Philip worked under the guidance of renowned cosmologist Dennis Sciama, an experience that further shaped his academic direction. A deep interest in quantisation of gravity led him to Texas, where he began collaborating with the esteemed American physicists John Wheeler, Bryce deWitt and Steven Weinberg. This partnership opened new doors and kept Philip in Texas for over two decades before he returned to the UK. “The science in Texas was exceptional, and what was meant to be a one-year postdoc turned into 21 years," Philip shares.

Partnership and Collaboration
As both scientists and life partners, Xenia and Philip share a profound connection that enhances their scientific endeavours. However, balancing the demands of family life with academic commitments has not been without its challenges. "It wasn’t easy," Xenia reflects, recalling the period that Philip commuted on a weekly basis between Austin and Princeton. They spent long stretches of time traveling between countries, with children in tow. Despite the difficulties, their shared passion for science and unwavering support for each other have kept them grounded.

"We like similar things, which makes working together very natural," Xenia notes. Their collaborative work focuses on how matter and the universe interact, with string theory, algebraic geometry, and number theory at its core. “Our collaboration is similar to any other collaboration, but we can be noisy in discussion,” Xenia laughs.

Together, Xenia and Philip have significantly advanced the intersection of mathematics and physics, particularly in string theory. Their research focuses on Calabi-Yau manifolds - complex geometric structures critical for describing the extra dimensions predicted by string theory. "We collaborate on many papers, and our discussions often continue at home," Xenia notes. By exploring the connections between these manifolds and number theory, they have uncovered deeper insights into dualities and symmetries within string theory, linking abstract mathematical concepts, such as number theory, with physical phenomena, including black hole physics.

Reflecting on their long-standing work, Philip remarks, "Our research over the last two decades has explored the role of number theory in physics, a field that continues to evolve." Their innovative approaches to number theory’s influence on the behaviour of fundamental laws of nature have opened new avenues of understanding.

A Shared Passion for Research and Nature
Reflecting on their time at MATRIX, Xenia and Philip share a deep appreciation for its unique environment which not only fosters academic exchanges but also offers a profound connection to Australia’s stunning landscape and wildlife.

Their involvement and participation in the MATRIX program, The Geometry of Moduli Spaces in String Theory, was particularly impactful. The program supported advancements in their ongoing projects, including refining mathematical models related to dualities in string theory and modular forms, which continue to expand the theoretical framework of the field. “MATRIX provides an immersive environment where discussions aren’t rushed. There’s time to deeply explore ideas and develop collaborations,” Xenia emphasises.

Beyond the academic rigor, the serene setting of MATRIX left a lasting impression. With a chuckle, Xenia remarks, “We’ve brought a large bag, filled with cameras and lenses, all the way from the UK to Australia, ready to capture and explore the stunning landscapes here.” Xenia and Philip fondly recall evenings spent photographing cockatoos and observing kangaroos, blending personal moments with professional focus. “The relaxed yet stimulating environment is ideal for fostering creativity and collaboration,” Philip remarks. “You’re enveloped by trees, away from a city or town, which is both inspiring and calming. It’s conductive to discussion." Philip adds.

Advice for the Next Generation
While Xenia and Philip acknowledge the similarities in academic structures worldwide, they emphasise the geographic isolation of Australia, underscoring the critical role of initiatives like MATRIX in fostering collaboration. “MATRIX brings people together and fosters collaborations. That’s very important,” Philip notes.
When asked for advice for young researchers, they emphasise the importance of building a strong network and avoiding isolation, particularly in regions where distance can hinder collaboration. “Avoid isolation - build a network of peers you can share ideas with. Be proactive!” Xenia advises. Philip adds, "Much of the best research also happens during informal walks or casual discussions. It’s about being open to connections."

Both encourage young researchers to be proactive in forming these connections, as collaboration is key to success in academia. In regions like Australia, where geographic isolation can pose challenges, leveraging technology and engaging in international forums can bridge gaps and foster meaningful connections. “This is our second visit to MATRIX, and we can’t wait to return,” they say with genuine excitement.

As Xenia and Philip continue their work at Oxford, they remain dedicated to advancing research and inspiring the next generation of mathematicians and physicists. Their journey is a testament to perseverance, collaboration, and a shared passion for discovery. Looking ahead, they are excited about the unexplored possibilities. “There are many interesting areas in physics and mathematics, but predicting where they will lead is difficult,” Philip reflects. Whether collaborating on complex research or hiking through the Australian landscape, they continue to fuel their creativity and deepen their connection. Their partnership is not only about pushing the boundaries of knowledge but also about embracing a life of curiosity, exploration, and shared discovery.