Publications

Our teams aspire to make discoveries that impact everyone, and core to our approach is sharing our research and tools to fuel progress in the field.

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Our teams aspire to make discoveries that impact everyone, and core to our approach is sharing our research and tools to fuel progress in the field.

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1 - 15 of 11631 publications
Preview abstract Recent reports have highlighted how mobile apps share user location data with third parties, risking user privacy and platform trust. Although location data is highly sensitive, when users grant apps location access, they may not know the full extent to which it is used. We study how requiring Android apps to show a reason for location access could impact developers, users, and the platform. We surveyed 323 Android app developers and found most supported such a requirement. The majority said it would have a positive impact on user privacy, trust for apps, and trust for Android, where impact on user trust for Android correlated most strongly with support. Many developers also said the intervention would increase the number of users granting location access. Yet their open-ended comments also revealed consistent concerns, such as apps providing dishonest reasons and platform verification. To study the impact on user behavior, we conducted a randomized controlled experiment with 2579 US Android users. We tested how users' decisions to grant location access were impacted by app type, whether reasons were included in the requests, and the content of the reasons, including monetization. We did not find the reasons impacted users' decisions; decisions were instead driven by app type and demographics. Yet we did find the reasons could have a positive impact on user perception for the platform when the reasons did not include using data for ads. Our findings provide insights into developers' willingness to implement privacy-enhancing changes, and expose limits to improving user privacy by simply adding information to user interfaces. View details
A 3D Scene Graphs Survey: Open Challenges and Future Directions
Dennis Rotondi
Francesco Argenziano
Sebastian Koch
Nathan Hughes
Martin Büchner
Johanna Wald
Lukas Schmid
Daniele Nardi
Abhinav Valada
Liam Paul
Luca Carlone
Kai Arras
Annual Review of Control, Robotics, and Autonomous Systems (ARCRAS), 10 (2027) (to appear)
Preview abstract 3D Scene Graphs (3DSGs) have emerged as a powerful representation for spatial AI by combining geometric grounding with semantic and relational abstractions of the environment. Their expressiveness has made them relevant to a broad range of problems in robotics and computer vision, including mapping, task and motion planning, scene understanding, and many others. However, the field remains fragmented: different communities adopt distinct formulations, construction pipelines, and evaluation protocols, making it difficult to compare methods, identify common assumptions, and assess remaining challenges for robust real- world deployment. This survey provides a unified and critical review of 3DSGs, with particular emphasis on open challenges and future directions. We first formalize 3DSGs under a common definition and analyze the principal modeling choices that characterize existing formulations, including node and edge attributes, hierarchical structure, dynamic scene representations, and affordance-aware extensions. We then review how 3DSGs are constructed from raw sensory observations, covering both learning-oriented and construction-oriented systems. Finally, we examine downstream applications and evaluation strategies, from intrinsic graph quality to task-level performance. To support the community, we also provide a dedicated website that organizes and extends the surveyed works. View details
Preview abstract This disclosure describes systems and methods for a multi-agent framework that can automate and scale cognitive work. The framework can, for example, use a cognitive assembly line of specialized computational agents to perform tasks such as research and drafting. A beneficial component could be an adversarial review panel (ARP), which is a multi-agent review system where distinct agent personas critique a generated draft from varied perspectives. The structured feedback from the ARP can be used to automatically iterate on and refine the work product. This approach can improve the intellectual rigor of generated content and reduce the time required for production, which may allow human operators to focus on activities such as strategic oversight and final validation. View details
Preview abstract Every abstraction layer in the modern software stack exists to solve legitimate problems—coordinating independent developers and enforcing trust across boundaries. However, each layer exacts a Cognitive Tax: overhead paid not for correctness, but for human coordination. Published measurements bound this non-computational overhead at ~59% across the ISA frontend, ABI, IEEE 754 logic, and per-die guard-band slack. We propose a shift from shipping static artifacts to distributing formal intent. Developer intent is translated into Z3 invariant bundles, which a local Neural-Symbolic Oracle then synthesizes into `Asemantic Code'—an artifact governed by load-time proof certificates and mathematically mutated to exploit the specific manufacturing physics of its execution die. View details
Preview abstract In some multi-stage software build pipelines, downstream compiler errors may be reported against ephemeral, machine-generated intermediate artifacts rather than original, human-written source code, which can make remediation challenging. A system and method may address this by intercepting a downstream error, mapping its location back to the original source file, and programmatically injecting a dormant suppression tag into the original source code. During a subsequent build, an intermediate transpiler can propagate this tag into a newly generated intermediate artifact. In the intermediate file, the tag may become active and be recognized by the downstream compiler as a directive to suppress the specific error. This approach can facilitate an automated remediation process for certain build failures that avoids direct modification of ephemeral files and uses the original source code as a record for suppression. View details
Regression Test Selection at Scale
Randall Parker
Laiba Mehnaz
Charlie Song
Michelle Wang
Daniel Lee
Brandon Stewart
Ilya Kavalerov
2026
Preview abstract Core libraries in massive codebases are dependency hot-spots with high code churn and an immense number of reverse dependencies. A small code change in these libraries can impact a vast number of clients, creating a massive blast radius of costly breakages if a bug or regression is submitted. To prevent expensive post-submit breakages, it is not feasible to test global dependencies during the pre-submit stage for each code change because of resource limitations and the desire for minimal developer friction. In this paper, we propose a novel ranking-based approach that utilizes a hybrid call graph to test global dependencies during the pre-submit stage. Our method leverages the call graph to select a per-commit subset of these global dependencies and to generate inexpensive graph structural features that allow our machine learning model to learn the complex relationships between library code changes and client tests to predict failures. Evaluating our approach on 10 high-impact core libraries with an average test suite size of 220,000, we demonstrate that a fixed budget of 2,000 tests per commit, representing just 0.9% of the total execution cost, effectively catches regressions for 40% of failing commits. View details
Preview abstract As artificial intelligence (AI) transitions from experimental pilot programs to mission-critical enterprise operations, traditional software-based security frameworks are proving insufficient against sophisticated infrastructure-level threats. This article introduces the concept of Silicon-Level Sovereignty, a first-principles approach to digital trust that anchors security in the physical hardware rather than the software stack. We examine the technical architecture of Hardware Root of Trust (RoT), specifically focusing on the roles of Trusted Platform Modules (TPMs) and Secure Enclaves in modern AI accelerators such as GPUs and TPUs. By leveraging cryptographic remote attestation, organizations can move from a model of assumed software integrity to one of verifiable hardware-level proof. The discussion provides a comparative analysis of industry-leading implementations, including NVIDIA’s Hopper architecture [1, 2], Google’s Titan-backed TPU v5p [3, 4], and Microsoft’s Azure Boost Cerberus system [5, 6], alongside the cluster-scale trust challenges presented by ultra-large systems like xAI’s Colossus [7]. The article concludes that Silicon-Level Sovereignty is no longer an optional security feature but a foundational requirement for establishing the integrity, privacy, and multi-tenant isolation necessary for high-stakes AI workloads. View details
Preview abstract Distributed federated SQL query engines frequently materialize query results into files in data lakes. Optimizing the sizes of these files (e.g., balancing their sizes) is crucial for the efficiency of not only the materialization queries themselves, but also subsequent queries that read these files. Existing techniques to manage file size include specifying output targets (e.g., number of partitions), using cardinality estimation for materialized data volume, performing full shuffles prior to materialization to obtain accurate statistics, and/or post (background) compactions to merge small files. All of these solutions have limitations in practice; they typically do not provide any strong guarantees or can be prohibitively expensive when they do (e.g., they require background compactions to merge small files, which requires additional I/O and CPU cost). Most of the existing techniques can produce many small files during materialization and are sensitive to data skew. In this paper, we propose a novel method that streamlines materialization within the same query execution and provides guarantees on the file sizes using statistics at runtime. Our approach does not require a full shuffle before the materialization operator in order to get accurate statistics, making it attractive and robust in practice. To show the effectiveness of our approach, we present production metrics from F1 Query at Google that has been running this functionality for the majority of its production workload over many quarters. Our approach reduces the number of files produced by a factor of 100 or more, and as a result, it avoids creating tens of billions of files per day, saving storage and computation cost. View details
Preview abstract Standard evaluations of backdoor attacks on text-to-image (T2I) models primarily measure trigger activation and visual fidelity. We challenge this paradigm, demonstrating that encoder-side poisoning induces persistent, trigger-free semantic corruption that fundamentally reshapes the representation manifold. We trace this vulnerability to a geometric mechanism: a Jacobian-based analysis reveals that backdoors act as low-rank, target-centered deformations that amplify local sensitivity, causing distortion to propagate coherently across semantic neighborhoods. To rigorously quantify this structural degradation, we introduce SEMAD (Semantic Alignment and Drift), a diagnostic framework that measures both internal embedding drift and downstream functional misalignment. Our findings, validated across diffusion and contrastive paradigms, expose the deep structural risks of encoder poisoning and highlight the necessity of geometric audits beyond simple attack success rates. View details
Preview abstract We prove the following asymptotically tight lower bound for k-color discrepancy: For any k ≥ 2, there exists a hypergraph with n vertices such that its k-color discrepancy is at least Ω(√n). This improves on the previously known lower bound of Ω(√n/ log k) due to Caragiannis et al. [CLS25]. As an application, we show that our result implies improved lower bounds for group fair division. View details
Preview abstract We introduce AMS (Activation-based Model Scanner), a tool that detects modifications to safety training in language models by measuring the geometric structure of safety-relevant concepts in activation space. Safety training creates measurable separation between harmful and benign content classes; certain safety modifications collapse or rotate this structure, while others leave it intact. We validate AMS across 14 model configurations spanning 4 architecture families (Llama, Gemma, Qwen, Mistral) and four safety-modification categories (instruction-tuned, base, abliterated, uncensored fine-tunes). Leave-one-out cross-validation of thresholds achieves 71% accuracy (10/14); bootstrap 95% confidence intervals on σ point estimates have median width 3.4σ and a substantial fraction of cells cross the PASS threshold under resampling. We further measure behavioral compliance on 20 stratified JailbreakBench prompts per model and find that σ on the harmful-content concept predicts compliance with Pearson r=−0.546 ( p=0.043 ); the rank-order Spearman correlation is weaker ( ρ=−0.423 , p=0.13 ). The structural signal predicts behavior directionally but with meaningful noise. Mechanistic analysis identifies a four-class taxonomy of safety-training modifications distinguished by activation-space signature: 1) training removal collapses cluster separation (e.g., base models, Dolphin variants: 0.5– 1.4σ ); 2) weight-orthogonalization-style abliteration both collapses separation and rotates the refusal direction (Llama-3.1-abliterated: σ=3.33 , direction cos sim 0.30); 3) rotation-without-collapse abliteration preserves cluster separation while rotating the refusal direction (Gemma-2-9b-abliterated: σ=4.54 , direction cos sim 0.84); and 4) behavioral fine-tuning that preserves both magnitude and direction (DarkIdol-1.2-Uncensored: σ=5.45 , direction preserved, 97% behavioral compliance). 1) and 2) AMS’s Tier 1 σ -threshold detects classes; 3) Tier 2 direction-similarity verification detects class; and 4) Class is undetectable by activation-only probing and represents a documented failure mode of the approach. We discuss threshold calibration, limitations of single-run measurement, and the open problem of detecting behavioral-only safety modifications. View details
Preview abstract Source-to-source compilers may perform inefficiently by executing transpilation passes on scripts that do not contain the specific language features a pass is designed to transform, potentially leading to redundant processing. A compiler can analyze a script to generate a per-script feature map, for example, by identifying language features in its abstract syntax tree (AST). Before executing a transpilation pass, the compiler can check this map and may bypass the pass for that script if the specific feature targeted by the pass is not present. This feature map can also be dynamically updated throughout the compilation process as other passes transform the code. This method of conditional pass execution based on content-aware analysis may reduce redundant AST traversals, which could decrease overall compilation time and computational resource consumption. View details
Preview abstract Large language models (LLMs) have shown promise in assisting cybersecurity tasks, yet existing approaches struggle with automatic vulnerability discovery and exploitation due to limited interaction, weak execution grounding, and a lack of experience reuse. We propose Code-RedTeam, a security-aware multi-agent framework designed to mirror real-world red-teaming workflows by integrating security-domain knowledge, code-aware analysis, execution-grounded iterative reasoning, and long-term memory. Code-RedTeam decomposes vulnerability analysis into coordinated discovery and exploitation stages, enabling agents to plan, execute, validate, and refine actions based on real execution feedback while learning from prior trajectories. Extensive evaluations on challenging security benchmarks demonstrate that Code-RedTeam consistently outperforms strong baselines across diverse backbone models, achieving over 60% attack success rate in vulnerability exploitation and up to 10% absolute improvement in vulnerability detection. Ablation and iteration studies further confirm the critical role of execution feedback, structured interaction, and memory for building robust and generalizable cybersecurity agents. View details
Preview abstract This writeup defines the Hydration Proxy Pattern, a framework for building stateful conversational data systems over stateless LLM APIs. It describes a platform-agnostic approach to decoupling persistence from the AI provider through secure server-side intermediation and hybrid storage tiers. The abstract provides a blueprint for managing the "Persistence Gap" in enterprise AI integrations, detailing high-level strategies for session history management, streaming, and multi-stage semantic grounding without disclosing specific internal implementation details. View details
Mind the Gap: Structure-Aware Consistency in Preference Learning
Proceedings of the 43rd International Conference on Machine Learning (ICML 2026)
Preview abstract Aligning Large Language Models (LLMs) with human intent, whether through explicit reward modeling or direct methods such as DPO, fundamentally relies on minimizing a surrogate loss as a proxy for the true pairwise ranking objective. We prove that this reliance is flawed for the standard surrogate losses used: for the equicontinuous hypothesis sets characteristic of neural networks, no standard surrogate provides a meaningful consistency guarantee. Minimizing the surrogate loss to zero can leave the true ranking error arbitrarily high. To resolve this, we formulate LLM alignment within a margin-shifted ranking framework and derive $H$-consistency bounds showing that enforcing a confidence margin $\gamma$ is not merely beneficial but necessary for consistency. We further introduce Structure-Aware $H$-consistency and a corresponding objective (SA-DPO) that adapts the margin to the semantic distance between responses, preventing instability on near-synonymous pairs. Finally, we analyze the trade-off between the margin required for consistency and the model's finite capacity to satisfy it, revealing a strict hierarchy of surrogate losses: heavy-tailed surrogates (e.g., the Polynomial Hinge family) offer strictly superior consistency guarantees for capacity-bounded models compared to the logistic loss used in DPO. Experiments on UltraFeedback and Argilla DPO-Mix-7k confirm that SA-DPO consistently outperforms DPO and SimPO, with a 58.5% head-to-head win-rate in downstream generation quality. View details
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