# Metaverse Meets Smart Cities--Applications, Benefits, and Challenges
## 1 Introduction
Digitization measures are being implemented in municipal and urban structures, and established processes are being revised [16]. The metaverse offers approaches to digitalization and can strengthen citizens' social community. This creates the first contact points between the metaverse and smart city applications. The concept of smart cities is based on data and technologies that record a wide range of conditions in the city, making them more efficient and livable. IoT sensors, in particular, are used to provide access to the data sources. The data collected forms the basis for processing with AI and data science methods and generates data-based insights. The existing data are an ideal basis for use in the metaverse, as interfaces are available and a comprehensive infrastructure is established [17]. The metaverse supplements the smart city with essential components, such as virtual participation in urban planning processes, to enable citizens' involvement. For example, the German city of Aalen plans a virtual town hall meeting to foster direct communication between citizens, administration, and politics [18]. Furthermore, smart city metaverse applications can make life much easier by integrating virtual citizen services, remote workplaces, real-time traffic and transportation information, and education and health services. By closely connecting the real and virtual worlds, cities can respond more effectively to challenges such as traffic management, environmental protection, and energy efficiency [4]. However, there are ethical and social issues to consider, such as data protection, the security of virtual spaces, and potential social inequality in access to technologies [19]. Nevertheless, the potential applications of the metaverse in the smart city sector offer a promising opportunity to transform cities and shape people's lives in new, innovative ways. As the metaverse can be used in many areas and affects different areas of people's lives, it is essential to identify how it can be used effectively in the urban environment. This gives rise to the following research questions:  
What potential use cases does the metaverse offer in the smart city sector, and what applications and benefits are there? Which challenges do smart city metaverse applications inherit? By answering these research questions, the study contributes a comprehensive overview of potential and already implemented metaverse applications in the context of cities and municipalities. This indicates which applications have already been implemented and which are still waiting to be realized. In addition, challenges related to these applicationsare identified. Thus, the paper provides researchers and practitioners with a guide to smart city metaverse applications. It identifies potential benefits and challenges and indicates which stakeholders in a municipality are affected. Furthermore, the study indicates which smart city metaverse applications are specifically popular, i.e., which applications have already been implemented frequently. The remaining paper is structured as follows: Section 2 presents the metaverse technology stack. The current state of research on the metaverse in the smart city context is described and analyzed in Section 3 to provide context for this paper. The Section 4 presents the research methodology used and the material generated. This includes explaining the steps and techniques used to collect and analyze the data. Section 5 presents the research outcomes, including potential metaverse applications in the smart city context and concrete examples from real-world practice. The challenges for the smart city metaverse are identified. The findings are then discussed in Section 6, examining advantages and disadvantages and possible solutions. Finally, Section 7 summarizes the paper's conclusions and provides an outlook on future developments.