Eitan Tadmor (Universty of Maryland), laureate of the FSMP Chair of excellence in 2023, is giving a doctoral course entitled Emerging Behavior in Collective Dynamics on Wednesdays from 14:00 to 17:00 , from Frebruary 7^th to March 27^th 2024 at Institut Henri Poincaré (11 rue Pierre et Marie Curie), in room 314 (salle Pierre Grisvard), except March 27^th when it will take place in room 201 (salle Maryam Mirzakhani).

Syllabus:

Nature and human societies offer many examples of self-organized behavior: ants form colonies, birds flock, mobile networks synchronize, and consensus may emerge from interaction of diverse human opinions. These are simple examples of collective dynamic in which small scale interactions of so-called active particles, lead to emergence of high-order, larger-scale patterns. These lectures will survey recent mathematical developments in collective dynamics, starting with the influential works of Reynolds, Krause, Vicsek and Cucker & Smale. The dynamics is governed by different protocols of pairwise interactions. Collisions are avoided. There is a hierarchy of three levels of descriptions: agent-based description of swarm dynamics on a graph, a Vlasov-type kinetic description, and large-crowd hydrodynamic description. A main question of interest is how different classes of interaction kernels affect the large-time, large-crowd, non-equilibrium dynamics, leading to the emergence of different large-scale patterns.

The French healthcare system is based on two main components:

- the basic state health insurance

- and supplementary health insurance (¨Mutuelle¨), a blend of public and private services. 

The basic state health insurance: Sécurité Sociale

The French social security system is based on the principle of ‘solidarity contributions’. Persons exercising a professional activity (employed or self-employed), or those resident on French territory on a continuous and legal basis, and their dependents, are entitled to healthcare, both in private practices and in hospitals, while benefiting from partial coverage of healthcare costs by France’s Social Security system (topped up with supplementary cover). Contributions are made through social security deductions from each person’s income.

3 minutes to understand the French Social Security system, an official video from Sécurité sociale.

Salaire brut/Net/chargé: what’s that supposed to mean?

Salarie chargé = Total to be paid by the employer. It is the global salary cost for the employer (gross salary + employer contributions)

Salaire brut = Gross Salary. The gross salary represents the amount due to the employee under the terms of his/her employment contract, before any mandatory tax deductions. The gross salary includes the remuneration of his/her actual working hours, as well as different commissions or bonuses. It also takes into account sick leaves, paid leaves or bank holidays.

Salaire net avant impôt sur le revenu = Amount to be paid before income tax. 

PAS or Prélèvement à la Source = Income tax deducted at source/Withholding tax

The Paris public transportation network serves the entire city and all (almost all) its suburbs.

The metro

The Métro is the cheapest, easiest and fastest way to get around Paris. There are 16 metro lines and some 300 metro stations; the entrance is indicated by a large yellow letter ‘M’.

Metros start running every day – including public holidays – at around 6am and stop at around 0:45am, except Friday and Saturday night when they stop at 1:45am.

The frequency at which metros run depends on the time and day: at peak hours, metros run every 2 to 4 minutes

If you are looking for financial support for your accommodation in France, you might already have heard for "CAF" at your University International Office or in some article on Internet. It means « Caisse d’Allocations Familiales », which is the French Family Benefit Fund (www.caf.fr). It provides some financial support to students to pay their accomodation rent as well.

What kind of help can I get from the CAF?

CAF can help you financially to pay your rent. 

CAF won’t find you any accommodation. You have to look for housing solution in Paris all by yourself. 

As someone who lives or makes money in France, you may pay taxes on:

• personal income on an annual basis,
• investments,
• corporate or business income,
• inheritance,
• property,
• wealth,
• purchased goods and services (taxe sur la valeur ajoutée TVA, or VAT).

Income tax

Once a resident in France, you are liable to pay taxes in France on your income:

• French income tax (impôt sur le revenu),
• Social security contributions (charges sociales/cotisations sociales). 

At the beginning of 2019, the Pay-As-You-Earn (PAYE) system is used universally throughout France. Instead of filing an income tax and paying whatever taxes you owe for the prior year, you’ll be taxed right at the source of the income, in monthly payments. Income subject to PAYE also includes retirement income (such as pensions or annuities), relevant overseas income, sick and maternity leave, and rental income.