Asymptotic stability of stochastic differential equations driven by Lévy noise

Using key tools such as Ito's formula for general semimartingales, Kunita's moment estimates for Levy-type stochastic integrals, and the exponential martingale inequality, we find conditions under which the solutions to the stochastic differential equations (SDEs) driven by Levy noise are stable in probability, almost surely and moment exponentially stable

Stability properties of stochastic differential equations driven by Lévy noise.

The main aim of this thesis is to examine stability properties of the solutions to stochastic differential equations (SDEs) driven by Levy noise. Using key tools such as Ito's formula for general semimartingales, Kunita's moment estimates for Levy-type stochastic integrals, and the exponential martingale inequality, we find conditions under which the solutions to the SDEs under consideration are stable in probability, almost surely and moment exponentially stable. In addition, stability properties of stochastic functional differential equations (SFDEs) driven by Levy noise are examined using Razumikhin type theorems. In the existing literature the problem of stochastic stabilization and destabilization of first order non-linear deterministic systems has been investigated when the system is perturbed with Brownian motion. These results are extended in this thesis to the case where the deterministic system is perturbed with Levy noise. We mainly focus on the stabilizing effects of the Levy noise in the system, prove the existence of sample Lyapunov exponents of the trivial solution of the stochastically perturbed system, and provide sufficient criteria under which the system is almost surely exponentially stable. From the results that are established the Levy noise plays a similar role to the Brownian motion in stabilizing dynamical systems. We also establish the variation of constants formula for linear SDEs driven by Levy noise. This is applied to study stochastic stabilization of ordinary functional differential equation systems perturbed with Levy noise

Asymptotic stability of stochastic differential equations driven by Lévy noise

Using key tools such as Ito's formula for general semimartingales, Kunita's moment estimates for Levy-type stochastic integrals, and the exponential martingale inequality, we find conditions under which the solutions to the stochastic differential equations (SDEs) driven by Levy noise are stable in probability, almost surely and moment exponentially stable

Asymptotic Stability of Stochastic Differential Equations Driven by Lévy Noise

Using key tools such as Itô's formula for general semimartingales, Kunita's moment estimates for Lévy-type stochastic integrals, and the exponential martingale inequality, we find conditions under which the solutions to the stochastic differential equations (SDEs) driven by Lévy noise are stable in probability, almost surely and moment exponentially stable.</jats:p

Asymptotic Stability of Stochastic Differential Equations Driven by Lévy Noise

Using key tools such as Itô's formula for general semimartingales, Kunita's moment estimates for Lévy-type stochastic integrals, and the exponential martingale inequality, we find conditions under which the solutions to the stochastic differential equations (SDEs) driven by Lévy noise are stable in probability, almost surely and moment exponentially stable.</jats:p

Conspiracy Theories, Trust in Science, and Knowledge during the Third Wave of the COVID-19 Pandemic in Cyprus

Conspiracy theories flourish during periods of crisis. One way to counteract the believability of conspiracy theories is trust in science and knowledge about the &ldquo;perceived threat&rdquo;, such as the SARS-CoV-2 virus. A total of 363 adults from Cyprus were recruited via convenience and snowball sampling methods. The data were collected via an internet-based questionnaire that examined participants&rsquo; belief in 17 conspiracy theory statements, trust in science and scientists, knowledge about the symptoms and the spread of the SARS-CoV-2 virus, phobic anxiety, hostility, somatization, and personality traits based on the Big Five. The results suggest (a) the overall belief in conspiracy theories in Cyprus is low, even though a notable percentage holds a neutral stance towards these theories; (b) trust in science and knowledge about the symptoms and the spread of the SARS-CoV-2 virus is negatively related to conspiracy theories, indicating the importance of trusting science and having knowledge as a means to counteract conspiracy theories; (c) young adults, those residing in rural areas, and those with a low education level are more likely to believe in conspiracy theories; (d) there are no significant associations between conspiracy theories and the psychological dimensions of phobic anxiety, hostility, and somatization; (e) there is difficulty in identifying specific traits related to conspiracy ideation. Public health officials could benefit from the findings when communicating information during periods of crisis

The Role of Conspiracy Theories, Perceived Risk, and Trust in Science on COVID-19 Vaccination Decisiveness: Evidence from Cyprus

COVID-19 reminded us of the importance of vaccinating for successfully overcoming health-related crises. Yet, vaccine hesitancy is still present. This study examined the impacts of conspiracy theories, perceived risk, and trust in science on COVID-19 vaccination decisiveness. The study was conducted at the end of the third wave of the pandemic, in July 2021, in Cyprus. Data were collected via an online self-administered anonymous survey using convenience and snowball sampling methods. Participants were 363 adults who completed a set of questionnaires that examined their believability in ten vaccine-related conspiracy theories, their perceived dangerousness of COVID-19, and their level of trust in science and scientists. The results suggest that (a) participants with a high conspiracy theory belief are less likely to be vaccinated, (b) participants who perceive COVID-19 as a dangerous disease are more likely to be vaccinated, and (c) participants with high trust in science are more likely to be vaccinated. The implications of the findings are discussed and can be used by public health officials in their campaigns.</jats:p

Nomophobia, Attachment Styles, and Loneliness: A Study Among Adults in Cyprus

The rapid increase in global smartphone usage and the range of capabilities they offer have resulted in an overdependence on them, leading to the term nomophobia. Nomophobia refers to the psychological discomfort or anxiety experienced when an individual is unable to use or does not have access to their mobile phone, and it is a phenomenon that warrants research attention due to its psychological and social implications. The aim of the current study was to examine the relationship between nomophobia and the time spent on mobile usage, attachment in close romantic relationships, and loneliness. Participants included 300 adults from Cyprus who were recruited through convenience and snowball sampling methods. Data were gathered using an internet-based questionnaire that assessed participants&rsquo; time spent on mobile usage, their attachment styles in close relationships, and their level and type of loneliness. The results suggest that (a) anxiety dimension and time spent on mobile phone are significant predictors of nomophobia, (b) higher levels of nomophobia are associated with an insecure attachment style, (c) more severe levels of nomophobia are associated with higher levels of loneliness, and (d) increased time spent on mobile usage is linked to higher levels of nomophobia. The findings suggest that the widespread emergence of nomophobia raises important concerns, highlighting the need for the development of educational programs that promote balanced mobile usage and encourage direct social interaction. The significance of targeted interventions that address mobile phone regulation and attachment-related vulnerabilities is emphasized

The Impact of the COVID-19 Pandemic on Mental Health: Evidence from Cyprus

The aim of the current study was to examine mental health effects of the first wave of COVID-19 (Corona Virus Disease-19) in Cyprus. Accordingly, 388 individuals aged 18–65+ responded to the Components of Mental Health Questionnaire that was distributed via social media for two weeks assessing how emotional distress, support and interest in self and others, lifestyle changes, engagement in protective measures, and avoidant behaviors were related to participants’ gender, age, and place of residency. Additionally, we measured the level of concern of individuals during and after the first wave outbreak of the pandemic. The results suggest that (a) females experience higher levels of anxiety, stress, fear, worry, and despair than males and are more likely to undertake protective measures, (b) older individuals and those who live in urban areas perceive greater social support and interest in the emotional experience of significant others, (c) emotional distress and support and interest in self and others are associated with all other variables, indicating the importance of these constructs to the experience of a pandemic, and (d) there was a decrease in participants’ concern after the end of the first wave of the pandemic. Mental health professionals could find this information useful when developing and implementing prevention programs that aim to offer psychological support during this stressful period.</jats:p