Bøker av Jakob Nielsen

In today's fast-paced and demanding world, stress has become an inevitable part of our lives. Whether you are a student, a working professional, a parent, or just someone trying to navigate through the challenges of daily life, stress can take a toll on your mental and physical well-being. That's why it is crucial to understand the importance of stress management and learn effective strategies to cope with it.Stress, if left unmanaged, can have detrimental effects on both your physical and mental health. It can lead to chronic illnesses such as high blood pressure, heart disease, and even depression. Moreover, stress negatively impacts your cognitive abilities, making it difficult to concentrate, solve problems, and make rational decisions. It can also affect your relationships, causing conflicts and a general sense of dissatisfaction in your personal and professional life.Proper stress management is the key to leading a healthy and fulfilling life. It helps you regain control over your emotions, thoughts, and behaviors, allowing you to handle challenging situations with resilience and clarity. By mastering stress management techniques, you can enhance your overall well-being and achieve a greater sense of fulfillment.One effective strategy for managing stress is setting realistic goals. When you set achievable goals, you create a sense of purpose and direction in your life. This helps alleviate stress by providing you with a clear roadmap to follow, reducing feelings of uncertainty and overwhelm. By breaking down larger goals into smaller, manageable tasks, you can make progress step by step, which boosts your confidence and reduces stress levels.Another crucial aspect of stress management is self-care. Taking care of yourself both physically and mentally is essential in combating stress. Engaging in activities that promote relaxation and rejuvenation, such as exercise, meditation, and hobbies, can significantly reduce stress levels. Additionally, maintaining a healthy lifestyle through proper nutrition, regular sleep patterns, and a balanced work-life routine can greatly contribute to stress reduction.

This is an introductory textbook on isometry groups of the hyperbolic plane. Interest in such groups dates back more than 120 years. Examples appear in number theory (modular groups and triangle groups), the theory of elliptic functions, and the theory of linear differential equations in the complex domain (giving rise to the alternative name Fuchsian groups). The current book is based on what became known as the famous Fenchel-Nielsen manuscript. Jakob Nielsen (1890-1959) started this project well before World War II, and his interest arose through his deep investigations on the topology of Riemann surfaces and from the fact that the fundamental group of a surface of genus greater than one is represented by such a discontinuous group. Werner Fenchel (1905-1988) joined the project later and overtook much of the preparation of the manuscript. The present book is special because of its very complete treatment of groups containing reversions and because it avoids the use of matrices to represent Moebius maps. This text is intended for students and researchers in the many areas of mathematics that involve the use of discontinuous groups.