Schedule

Registration & Opening Words

Bum-Hoon Lee (Sogang U.)

Title: "High‑Frequency Gravitational Waves and Higher-Curvature Effects: A Future Direction"

Abstract: We study high-frequency gravitational waves in Einstein–dilaton–Gauss–Bonnet (EdGB) gravity, a minimal extension of Einstein gravity that incorporates higher curvature corrections. EdGB gravity introduces qualitative new features. These early universe modifications directly affect gravitational wave production. In particular, the hot primordial plasma generates the Cosmic Gravitational Microwave Background (CGMB), whose amplitude is extremely small in ΛCDM. In contrast, EdGB dynamics naturally enhance the CGMB signal, potentially bringing it within reach of future high-frequency gravitational wave detectors. This provides a promising observational avenue for constraining higher curvature gravity.

Leopoldo Soto (CCHEN)

Title: "Scaling Down without Scaling Away the Physics: Compact Pulsed Plasmas, Fusion, and Matter Far from Equilibrium"

Abstract: Can compact experiments contribute to nuclear fusion and extreme-matter research? The answer depends on accessing relevant physical regimes and preserving scaling relations, not merely on size or stored energy. This talk presents research developed at the Chilean Nuclear Energy Commission using dense plasma focus devices. Our aim was to establish scaling rules enabling compact experiments to reproduce plasma conditions found in megajoule-class devices. Extending these rules into the sub-joule regime, we showed that devices spanning more than six orders of magnitude in stored energy can maintain comparable ion density, magnetic field strength, plasma-sheath velocity, Alfvén speed, energy density, and energy per particle. Under appropriate conditions, they can reach comparable temperatures despite very different total energies. However, characteristic times, collisionality, radiation losses, boundary effects, diagnostic accessibility, and pinch stability may scale differently. This leads to a broader question: how does matter respond when energy is deposited faster than its relaxation processes? Small plasma focus devices concentrate modest energies into 10–100 ns pulses, creating extreme conditions of matter and producing radiation, energetic particles, fusion neutrons, plasma jets, and shock waves. Two examples will be discussed: transient loading of fusion-relevant materials and cancer radiobiology using nanosecond X-ray pulses at ultra-high intrapulse dose rates.

Patricio Salgado-Rebolledo (APCTP)

Title:  String-like fractons and and higher-rank gauge theory

Abstract: Fracton gauge theories can be obtained by gauging extensions of the Aristotelian algebra that include an Abelian charge and its associated dipole moment. Alternatively, such gauge theories arise from the dualization of Cosserat elasticity. In this talk, I will briefly review these approaches in the case of point-like fractons and then extend them to derive a model of higher-rank gauge fields that naturally couple to line-like fractonic excitations, or fracton strings.

Simón Poblete

Title: Computer simulations of biological systems at different scales: the case of nucleic acids

Abstract: Nucleic acids are fundamental to all living organisms. The continuing discovery of their diverse biological functions has driven the development of novel therapeutic strategies and has even given rise to the RNA world hypothesis, which proposes that the earliest forms of life on Earth were based on ribonucleic acid (RNA).

Molecular dynamics (MD) simulations represent the gold standard for achieving atomistic descriptions of biomolecular systems. However, for nucleic acids, their predictive power is limited by the approximations inherent to classical representations, which do not account for quantum mechanical effects, as well as by the restricted spatial and temporal scales accessible to simulation. In this talk, we will describe how complementary approaches spanning polymer theory, statistical mechanics, density functional theory, and molecular dynamics can be integrated to provide multiscale descriptions of nucleic acids. We will illustrate this strategy through two case studies: the packaging of viral genomes in small icosahedral viruses and the conformational landscape of adenosine monophosphate dinucleotide in aqueous solution.

Coffee Break

Hyun-Sik Jeong (APCTP)

Title: "Neural Network-Based Methods for Inverse Problems in Holography "

Abstract: Holography (AdS/CFT) provides a powerful framework for studying the quantum nature of gravity and strongly coupled quantum systems. This talk showcases how deep neural networks can address inverse problems in holography: specifically, reconstructing bulk gravity models from boundary observables. By integrating holography with physics-informed neural networks, we show that strongly coupled systems, from QCD-like theories to condensed-matter models and entanglement-based setups, can be analyzed in a data-driven and robust way. The aim is to demonstrate how machine-learning methods enable stable, consistent reconstructions and offer new insights that complement traditional holographic approaches.

Guillermo Romero (USACH)

Title: Floquet engineering in many-body systems 

Abstract: Periodically driving a quantum many-body system can drastically change its properties, leading to exotic non-equilibrium states of matter without a static analog. In this scenario, parametric resonances and the complexity of an interacting many-body system are pivotal in establishing non-equilibrium states. Considering a one-dimensional lattice described by the transverse field Ising model, we show how Floquet engineering allows us to establish spatio-temporal localization of entanglement quantified by pairwise concurrences. Also, we show how many-body resonances modulating spin-spin exchange or individual spin gaps inhibit interactions between spins, thus proving a mechanism for controlling spin-wave propagation and a quantum switch. The schemes may be implemented in circuit QED with direct applications in coupling–decoupling schemes for system-reservoir interaction and routing in quantum networks.

Sebastián Allende (USACH)

Title: From Edge-Guided Bimerons to Magnetic Worms: Collective Topological Transport in Nanostripes

Abstract:  We investigate how magnetic boundaries and engineered defects can be exploited to control the current-driven transport of bimerons in thin magnetic strips. We first demonstrate that an asymmetric bimeron-edge interaction can confine bimerons near the boundary, preventing their annihilation and enabling stable, accelerated propagation along both straight and curved racetracks(1). We further show that this mechanism supports the robust transport of bimeron chains. Building on this idea of using geometrical features to control bimeron dynamics, we then examine domain-wall bimerons propagating through periodically patterned nanostripes (2). We find that the interplay between defect-induced pinning and inter-bimeron interactions produces sustained oscillations in their relative separation while their center of mass continues to propagate. For multiple domain-wall bimerons, these oscillations become desynchronized, giving rise to a segmented collective motion that we identify as a magnetic worm. Our results establish boundaries and periodic defects as active design elements for controlling topological transport, oscillatory dynamics, and collective states in spintronic devices.

1) M. Castro, D. Gálvez-Poblete, S. Castillo-Sepúlveda, V. L. Carvalho-Santos, A. S. Nunez, and S. Allende, “Bimerons as Edge States in Thin Magnetic Strips,” Nano Letters 25, 7249–7257 (2025).

2) J. Toledo-Marin, M. Castro, D. Gálvez-Poblete, B. Grossi, S. Castillo-Sepúlveda, A. S. Nunez, and S. Allende, “Magnetic worms: Oscillatory domain wall bimeron pairing and collective transport in patterned stripes,” Physical Review B 113, 174420 (2026).

Luis Inzunza (USACH)

Title: Quasi-Integrable Dirac Materials

In recent years, our research group has focused on studying a new type of Darboux transformation applicable to two-dimensional Dirac-type equations. In contrast to its well-known one-dimensional counterpart, this transformation only allows for the construction of solvable models for a single energy level; that is, the generated systems are quasi-integrable. This property serves as a bridge between pure mathematics and electronic device design. Generally, this energy level possesses a higher degree of symmetry than the Hamiltonian itself, and the transport properties of the conduction electrons prove to be remarkably unique. To date, we have successfully constructed models exhibiting super-Klein tunneling (linking the phenomenon to integrable systems with infinite degrees of freedom), confining potentials in the form of quantum rings and dots, periodic crystal lattices with their corresponding Bloch states, invisible systems, and intricate spin textures. In this presentation, we will review the inner workings of this transformation and discuss some of the most relevant models generated through this procedure. 

Break / Transition

Lunch

Santiago City Tour